How Effective Is The Flu Vaccine 2020

Role Of The Pharmacist

Pharmacists play an important role in combating the influenza virus. With a growing number able to vaccinate, pharmacists can not only help immunize but also educate the community and dispel misconceptions surrounding vaccines. With the flu season fast approaching, it is imperative that as many individuals as possible are vaccinated in a timely and safe manner.

What Are Factors That Influence How Well Flu Vaccines Work

How well flu vaccines work can vary from season to season. Protection can vary depending on who is being vaccinated. At least two factors play an important role in determining the likelihood that vaccination will protect a person from flu illness: 1) characteristics of the person being vaccinated , and 2) how well the vaccines match the flu viruses spreading in the community. When flu vaccines are not well matched to one or more circulating influenza viruses, it is possible that vaccination may provide little or no protection from illness caused by those viruses, but still provide protection against other flu viruses that circulate during the season. When there is a good match between flu vaccines and circulating viruses, vaccination provides substantial benefits by preventing flu illness and complications. .

Each flu season, researchers try to determine how well flu vaccines work as a public health intervention. Estimates of how well a flu vaccine works can vary based on study design, outcome measured, population studied and type of flu vaccine. Differences between studies must be considered when results are compared.

When To Get Your Flu Shot

The CDC recommends getting your flu shot in early fall, between now and the end of October. That part is normal: The timing helps prepare your immune system before flu activity peaks, usually between December and February.

“Similar to the Covid vaccine, it takes a couple of weeks after you’ve had the vaccine for your immune system to respond,” Rock says. “So, you want to make sure that you have adequate immunity when we start into the flu season.”

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Why The Flu Vaccine Matters More This Year

This season, the flu will be “a little bit unpredictable,” Dr. Clare Rock, associate professor of medicine in the Division of Infectious Diseases at Johns Hopkins School of Medicine, tells CNBC Make It.

One reason: Scientists usually develop the annual influenza vaccines based on the composition of the flu strains that circulated the year before. Last year’s anomaly means it’s trickier to make this year’s vaccine, Rock says.

When vaccines are “well-matched” to the circulating flu virus, they can reduce the risk of illness by between 40% and 60%, according to the Centers for Disease Control and Prevention. This year’s number may be harder to predict.

That’s no reason to forgo your flu shot this year. No vaccine is ever 100% effective, and if you’re vaccinated, you’re significantly less likely to get severely ill. “The thought is that this flu vaccine this year is going to be as effective as it typically is,” Rock says. “But there’s just one more challenge that has gone into the mix.”

Another challenge: the potential of the flu and Covid circulating at the same time. “During the Covid pandemic, there are troubles potentially around every corner,” Rock says. “So I think the premise that we’re taking really is prepare for the worst and hope for the best.”

For perspective, that’s about three times as many flu-related hospitalizations as the U.S. typically sees in a year.

What Is In The Flu Shot

Every year, scientists around the world do their best to get one step ahead of the flu by developing that years iteration of the flu shot. As a reminder, vaccines work by giving your body a chance to fight off an altered version of a virus or bacteria, so that if and when it encounters the live virus in the wild, it already knows how to react, and you never get sick. But whats in a flu shot is a little more complicated.

The recipe starts with the four most common influenza strains from around the world, injected into fertilized chicken eggs or mammalian cells, deactivated so it doesnt give you the actual flu, mixed with a grab-bag of preservatives, antibiotics, and sugars. This combination is then formulated for a shot or spray to make it in time for the 2021 flu season. For those science-is-fucking-awesome types out there, this is indeed awesome.

Its also complex as hell something that keeps virologists on their toes every year. Influenza strains constantly mutate, but scientists get one shot at the annual vaccine, making their best guess some 30 weeks in advance to get the flu shot out to the public.

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Why We Need New Flu Vaccines Every Year

There are several reasons a new flu vaccine must be made each year.

Flu viruses can change from year to year, so the vaccine is updated to protect against new virus strains that are expected to circulate in the U.S. The vaccine needs to include influenza virus strains that most closely match those in circulation for the influenza season. In addition, the protection provided by the flu vaccine a person received in the previous year will diminish over time and may be too low to prevent influenza disease into next years flu season.

Iii2 People Capable Of Transmitting Influenza To Those At High Risk Of Influenza

People who are potentially capable of transmitting influenza to those at high risk should receive annual vaccination, regardless of whether the high-risk individual has been vaccinated. Vaccination of HCWs decreases their own risk of illnessFootnote 52,Footnote 53, as well as the risk of death and other serious outcomes among the individuals for whom they provide careFootnote 54,Footnote 55,Footnote 56,Footnote 57. Vaccination of HCWs and residents of nursing homes is associated with decreased risk of ILI outbreaksFootnote 58.

People who are more likely to transmit influenza to those at high risk of influenza-related complications or hospitalization include:

• HCWs and other care providers in facilities and community settings who, through their activities, are capable of transmitting influenza to those at high risk and
• Contacts, both adults and children, of individuals at high risk, whether or not the individual at high risk has been vaccinated.

Health care workers and other care providers in facilities and community settings

Vaccination of health care workers and other care providers

Outbreak management in health care facilities

Contacts of individuals at high risk of influenza complications

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When Is The Flu Season

According to the CDC, each flu season starts during the Morbidity and Mortality Weekly Report week 40. The season then lasts through week 39 of the next year.

This means that the 2018-2019 flu season will not officially end until September 28th, 2019. Until that time we do not have definitive numbers to illustrate the effect of the flu on the U.S. population and the effectiveness of the flu vaccine for that flu season. We do have a general idea of the season thanks to regular reports from the CDC, but final statistics wont be clear for months.

But, the 2017-2018 influenza season was a particularly severe season. It not only had a higher rate of outpatient visits and hospitalizations, but also had a notably longer duration of high influenza activity. At the end of the flu season it was reported that the vaccine had a 30% effectiveness. Although, due to the constantly changing strains with the viruses, the flu vaccine is said to be successful with a rate of around 40%.

The CDC reports that during the 2017-2018 season the flu vaccine is estimated to have prevented 7.1 million illnesses, 3.7 million medical visits, 109,000 hospitalizations, and 8,000 deaths.

Testing And Treatment Of Respiratory Illness When Sars

While waiting on results of testing, sick non-hospitalized persons with respiratory symptoms should self-isolate at home. Even if people test negative for both viruses, they should self-isolate because of the potential for false negative testing results depending upon what kind of test was done and the level of SARS-CoV-2 and influenza transmission in the community. Persons not hospitalized but who are at high-risk for complications from influenza should get antiviral treatment for influenza as soon as possible.

For hospitalized patients, empiric oseltamivir treatment for suspected influenza should be started as soon as possible regardless of illness duration, without waiting for influenza testing results. Get more information on testing and treatment when SARS-CoV-2 and influenza viruses are co-circulating.

CDC has developed clinical algorithms that can help guide decisions for influenza testing and treatment when SARS-CoV-2 and influenza viruses are co-circulating.

Influenza antiviral medications have no activity against SARS-CoV-2 viruses, nor do they interact with medications used for treatment of COVID-19 patients. If a patient who is at high risk for serious influenza complications is diagnosed with SARS-CoV-2 and influenza virus co-infection, they should receive influenza antiviral treatment.

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What Are The Benefits Of Flu Vaccination

There are many reasons to get an influenza vaccine each year. Flu vaccination is the best way to protect yourself and your loved ones against flu and its potentially serious complications.

Below is a summary of the benefits of flu vaccination and selected scientific studies that support these benefits.

• Flu vaccination can keep you from getting sick with flu.

• Flu vaccination prevents millions of illnesses and flu-related doctors visits each year. For example, during 2019-2020 flu vaccination prevented an estimated 7.5 million influenza illnesses, 3.7 million influenza-associated medical visits, 105,000 influenza-associated hospitalizations, and 6,300 influenza-associated deaths.
• During seasons when flu vaccine viruses are similar to circulating flu viruses, flu vaccine has been shown to reduce the risk of having to go to the doctor with flu by 40 percent to 60 percent.

• Flu vaccination has been shown in several studies to reduce severity of illness in people who get vaccinated but still get sick.
• A 2021 studyexternal icon showed that among adults, flu vaccination was associated with a 26% lower risk of ICU admission and a 31% lower risk of death from flu compared to those who were unvaccinated.

• A 2018 study showed that from 2012 to 2015, flu vaccination among adults reduced the risk of being admitted to an intensive care unit with flu by 82 percent.

Should I Get My Child Vaccinated

Yes, a flu vaccine offers the best defense against getting the flu and spreading it to others. Children younger than 5 years of age especially those younger than 2 years old are at high risk of serious flu-related complications.

Flu vaccination has been found to reduce deaths in children. A study in Pediatrics was the first of its kind to show that influenza vaccination is effective in preventing influenza-associated deaths among children.

Nationally, a total of 199 pediatric deaths had been reported to CDC during the 2019-2020 season.

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Iii1 People At High Risk Of Influenza

All pregnant women

NACI recommends the inclusion of all pregnant women, at any stage of pregnancy, among the particularly recommended recipients of IIV, due to the risk of influenza-associated morbidity in pregnant womenFootnote 25,Footnote 26,Footnote 27,Footnote 28,Footnote 29, evidence of adverse neonatal outcomes associated with maternal respiratory hospitalization or influenza during pregnancyFootnote 30,Footnote 31,Footnote 32,Footnote 33, evidence that vaccination of pregnant women protects their newborns from influenza and influenza-related hospitalizationFootnote 34,Footnote 35,Footnote 36,Footnote 37, and evidence that infants born during influenza season to vaccinated women are less likely to be premature, small for gestational age, and of low birth weight than if born to women that had not received an influenza vaccineFootnote 38,Footnote 39,Footnote 40,Footnote 41. The risk of influenza-related hospitalization increases with length of gestation .

Refer to the Statement on Seasonal Influenza Vaccine for 2011-2012 and the Statement on Seasonal Influenza Vaccine for 2012-2013 for further details on influenza vaccination during pregnancy.

Adults and children with chronic health conditions

Neurologic or neurodevelopment conditions

People of any age who are residents of nursing homes and other chronic care facilities

Adults 65 years of age and older

All children 6-59 months of age

Indigenous peoples

Ii5 Choice Of Seasonal Influenza Vaccine

The decision to include specific influenza vaccines as part of publicly funded provincial and territorial programs depends on several factors, such as cost-effectiveness evaluation and other programmatic and operational factors, such as implementation strategies. Not all products will be made available in all jurisdictions and availability of some products may be limited therefore, officials in individual provinces and territories should be consulted regarding the products available in individual jurisdictions.

With the availability of influenza vaccines that are designed to enhance immunogenicity in specific age groups or given through a different route of administration, the choice of product has become more complex.

Choice of influenza vaccine by age group

Recommendations for individual-level decision making

• NACI recommends that influenza vaccine should be offered annually to anyone 6 months of age and older who does not have contraindications to the vaccine. Table 2 provides age group-specific recommendations for the age-appropriate influenza vaccine types authorized for use in Canada.

Recommendations for public health program-level decision making

• NACI recommends that any of the age-appropriate influenza vaccine types available for use may be considered for people without contraindications to the vaccine. Table 2 provides age group-specific recommendations for the age-appropriate influenza vaccine types authorized in Canada.

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Who Should Have The Vaccine

In 2021/22 flu season, the following people are eligible to receive the flu vaccine for free:

• All children aged 2 to 15 on 31st Aug 2021
• Those aged 50 years or over
• Those in long-term residential care homes
• Carers
• Frontline health and social care workers
• Close contacts of immunocompromised individuals
• Those aged 6 months to 65 years in at-risk groups including people with the following health conditions:
• Respiratory diseases, including asthma
• Heart disease, kidney disease or liver disease
• Neurological conditions including learning disability
• Diabetes
• A severely weakened immune system , a missing spleen, sickle cell anaemia or coeliac disease
• Being seriously overweight

Babies under 6 months old are too young to receive a flu vaccine. This is because they have maternal antibodies passed on from their mother which prevent the vaccine from working so well. Flu vaccination is offered to all pregnant women in the UK . As well as protecting pregnant women themselves, this also helps to protect their newborn babies from flu.

Your doctor may recommend the flu vaccine in other circumstances as well.

How Does Cdc Measure How Well Flu Vaccines Work

CDC typically presents vaccine effectiveness as a single point estimate: for example, 60%. This point estimate represents the reduction in risk provided by a flu vaccine. CDC vaccine effectiveness studies measure different outcomes. For example, outcomes measured can include laboratory-confirmed flu illness , hospitalizations or intensive care unit admissions. For these outcomes, a VE point estimate of 60% means that on average the flu vaccine reduces a persons risk of that flu outcome by 60%.

In addition to the VE point estimate, CDC also provides a confidence interval for this point estimate, for example, 60% . The confidence interval provides a lower boundary for the VE estimate as well as an upper boundary . One way to interpret a 95% confidence interval is that if CDC were to repeat this study 100 times , 95 times out of 100, the confidence interval would contain the true VE value. Another way to look at this is that there is a 95% chance that the true VE lies within the range described by the confidence interval. This means there is still the possibility that five times out of 100 the true VE value could fall outside of the 95% confidence interval.

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What Flu Vaccine Should I Get

Different flu vaccines are approved for use in different groups of people. There are flu shots approved for use in children as young as 6 months of age and flu shots approved for use in adults 65 years and older. Flu shots also are recommended for use in pregnant women and people with chronic health conditions. The nasal spray flu vaccine is approved for use in non-pregnant individuals, 2 years through 49 years of age. People with some medical conditions should not receive the nasal spray flu vaccine. Your provider will know which flu vaccine is best for you.

How Does Cdc Measure How Well The Vaccine Works

Scientists continue to work on better ways to design, conduct and evaluate non-randomized studies to assess how well flu vaccines work. CDC has been working with researchers at universities and hospitals since the 2003-2004 flu season to estimate how well flu vaccine works through observational studies using laboratory-confirmed flu as the outcome. These studies currently use a very accurate and sensitive laboratory test known as real-time RT-PCR to confirm medically attended flu virus infections as a specific outcome. CDCs studies are conducted in sites located across the United States to gather data that accurately represents people and conditions across the country. To assess how well the vaccine works across different age groups, CDCs studies of flu vaccine effects have included all people aged 6 months and older recommended for an annual flu vaccination. Similar studies are being done in Australia, Canada and Europe.

• Baylor Scott and White Health
• Columbia University Irving Medical Center
• HealthPartners
• Intermountain Healthcare
• Kaiser Permanente Northern California
• Kaiser Permanente Northwest
• Regenstrief Institute
• University of Colorado .

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What You Need To Know About The 2021

While no one knows for sure just how bad the upcoming flu season will be, heres some flu information we know so far:

• The 2020-2021 flu season wasunusually mildcompared to whats been seen in past years. This could be due to multiple factors, including higher flu vaccination rates during 2020 and the effect the COVID-19 pandemic has had on social distancing and hand washing. Experts are not sure if this will be the case again for the 2021-2022 flu season.

• Flu transmission rates in other countries are lower than usual so far this year. The World Health Organization meets twice a year in February and September to review flu activity around the world and recommend which strains to include in the flu vaccine. Flu transmission in the Southern Hemisphere countries like Australia can help predict what the U.S. flu season might be like. Australia had a record low number of cases of the flu during 2021. Hopefully, that means we will too.

• Even though the flu vaccine doesnt protect against all strains of the flu, its still recommended for everyone over the age of 6 months. The flu vaccine is typically about 40% to 60% effective, and its hard to predict if the current flu vaccines will be a good match for the strains going around. But its still one of the best ways to help prevent getting sick with the flu.