Wednesday, September 27, 2023

Which Vaccine Is Effective Against Delta Variant

Coronavirus Faq: I’ve Been Vaccinated Do I Need To Worry About Variants

Sri Lanka Study Shows Sinopharm Vaccine Effective Against Delta Variant

“These new data are encouraging and reinforce our belief that the Moderna COVID-19 Vaccine should remain protective against newly detected variants,” Stéphane Bancel, Moderna’s chief executive officer, said in a statement. “These findings highlight the importance of continuing to vaccinate populations with an effective primary series vaccine.”

The company also said it is developing a booster candidate: a 50-50 mix of its currently authorized COVID-19 vaccine and another messenger RNA vaccine it has developed.

How We Can Protect Ourselves: Vaccine Effectiveness And Health Measures

Globally, and here in New Zealand, it is so important to stamp out any community outbreaks as quickly as possible and to ensure very high rates of vaccination.

Being fully vaccinated gives you protection against Delta infection and a very high degree of protection against severe illness, hospitalisation and death. Evidence currently shows:

  • the effectiveness of two doses of the Pfizer vaccine against symptomatic illness is 6495%
  • the effectiveness of two doses of the Pfizer vaccine against hospitalisation or severe disease due to Delta infection is about 9096%.

Some countries are reporting that the effectiveness of the vaccine against Delta infection may reduce over time. This is being monitored to help decision-making about whether booster doses of the vaccine may be needed in the future.

Vaccination does help to reduce transmission of the virus. Taking other precautions also remains important in order to continue to protect our communities against Delta. As well as vaccination, early detection of cases and swift contact tracing, and isolation of cases and contacts, is critical.

It will also be important to continue to protect ourselves and our whnau and stop the transmission of the disease by following health habits such as:

Further information on Delta and other variants of interest or concern may be seen on our Science News page.

Do You Need Booster Shots

In addition to the results of the singleshot study, on Sept 21, 2021, Johnson & Johnson released data about booster shots. The trial gave people a second dose of the Johnson & Johnson vaccine either two or six months after the first dose. In both cases, it increased peoples defense against COVID19. Maureen Ferran, a virologist at the Rochester Institute of Technology, said.

Participants who received a Johnson & Johnson booster shot two months after their initial dose were found to be 94% protected against developing moderate to severe COVID-19, and the number of antibodies present in their blood increased four-fold.

However, those who received a Johnson & Johnson booster shot six months after their first shot increased the number of antibodies in their blood 12-fold, in addition to exhibiting the 94% level of protection associated with the two-month booster.

All of the participants were assessed one month after receiving their booster shots.

These findings suggest that although a single dose of the Johnson & Johnson vaccine provides strong, durable protection, people may still benefit from a booster because it improves the vaccines efficacy, Ferran concluded.

Booster shots of the Johnson & Johnson and Moderna vaccines are not yet approved . Infectious disease expert Dr. Anthony Fauci said that the FDA may review booster data for the Johnson & Johnson vaccine within a few weeks.

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How Delta Is Different From Earlier Variants

Science is telling us the Delta variant has a number of differences compared to earlier variants of the virus. These differences mean that the Delta variant may be a greater threat to the health of individuals who contract the infection and a greater challenge to contain the spread of the virus in an outbreak. For example:

  • delta may cause people to develop more serious COVID-19 illness than other variants of the virus
  • people with a Delta infection may be at higher risk of needing hospital care
  • the chance of infecting others such as within your household or other contacts is very high because Delta is so transmissible. It is estimated that on average, without vaccination, one person infected with Delta may infect 5 or 6 other people. This is how Delta outbreaks in places overseas have grown so rapidly
  • people with Delta infections seem to carry much more virus and for a longer period of time than those infected with the original virus or other variants
  • the time from exposure to the virus until the first positive test is shorter for the Delta variant. On average, a person may be infectious for 12 days before they develop symptoms and some people who are infected never develop symptoms . Asymptomatic people may still be infectious, early on in their infection.

Pfizer 93% Effective Against Symptomatic Infection In Teens

AstraZeneca, Pfizer vaccines effective against Delta COVID ...

In Israel, the Clalit Research Institute, in conjunction with Harvard University, conducted an observational study involving 130,464 COVID-19naïve adolescents aged 12 to 18 years, half of whom were vaccinated with the Pfizer COVID-19 vaccine from Jun 8 to Sep 14, 2021 matched participants were unvaccinated. During the study, 13,423 unvaccinated participants were vaccinated.

At the time of the study, Delta was responsible for more than 95% of new infections in Israel. The study is the largest peer-reviewed look at COVID-19 vaccine efficacy among adolescents in a nationwide setting and the first such study conducted at a time when Delta was the dominant circulating strain.

Over a median of 27 days after receipt of the first vaccine dose, Kaplan-Meier curves for infection showed a similar incidence of infection in the first few days after the vaccinated group received their first dose, after which the rise in incidence slowed among the vaccinated.

Estimated effectiveness of the Pfizer vaccine against infection was 59% 14 to 20 days after the first dose, climbing to 66% on days 21 to 27 and 90% 7 to 21 days after the second dose.

Efficacy against symptomatic COVID-19 was estimated at 57% 14 to 20 days after the first vaccine dose, rising to 82% on days 21 to 27 and to 93% 7 to 21 days after the second dose.

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How Effective Are The Covid Vaccines Against The Delta Variant

Vaccine efficacy has been a main question as the delta variant continues to spread around the country.

Health experts have said that a majority of hospitalizations and deaths associated with the variant in recent months are almost entirely in unvaccinated individuals. The CDC has said the risk of infection is 8x higher in the unvaccinated than the vaccinated, and the risk of hospitalization or death is 25x higher.

But is one better than the other at protecting against breakthrough infections in vaccinated populations?

Researchers in Belgium directly compared the Pfizer and Moderna COVID-19 vaccines by testing the antibodies of 2,500 health care workers after two doses of both vaccines.

The study found the Moderna vaccine produced more than double the antibodies compared to Pfizer, but doctors urge caution.

Antibody level itself is interesting, but it doesnt necessarily lead to a significant difference in the way the vaccine is performing, said Dr. Allison Arwady, Commissioner of the Chicago Department of Public Health.

Another study to consider when comparing vaccines is one from the Mayo Clinic earlier this month, which is awaiting a full review.

That study found the risk of suffering a breakthrough COVID-19 infection with the delta variant after being fully vaccinated with the Moderna vaccine may be much lower than the risk for those who received the Pfizer vaccine.

Is The New Delta Plus Variant A Cause For Concern

Experts have stressed that there is no need to panic. As the coronavirus is moving towards an endemic stage, there will be waves of infection but not severe enough to cause deaths .

“Mutations of a virus is inevitable. Flu does that every year, why will COVID be any different? Please understand that just because we have found a mutant doesn’t mean it is a problem. The best we can do is vaccinate, which we have done aggressively. So, even if we do have a new wave, it will be so mild that it will not tax the system as it did this year,” said experts .

In recent months, the sub-lineage has become increasingly common in the UK, with some evidence suggesting that the variant may have an increased growth rate in the UK compared to Delta.

And more data is required to understand whether the increased growth is due to changes in the virus’ behaviour or epidemiological conditions .

“The genome of VUI-21OCT-01 does not have many mutations compared to Delta. However, a small change may be enough to cause a difference in the virus properties in some circumstances,” mentioned UKHSA .

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Fauci Warns Dangerous Delta Variant Is The Greatest Threat To Us Covid Efforts

The delta variant is now infecting at least 1 out of every 5 people who get the virus in the United States. In some sections of the country, the variant is already far more common, particularly in parts of the Midwest and West. At its currentpace, the delta variant is expected to be the dominant virus in the U.S. within weeks.

Dr. Maria Van Kerkhove, an infectious disease expert at the World Health Organization, called the delta variant “incredibly transmissible.”

“These viruses are becoming more fit. The virus is evolving, and this is natural,” she told NPR’s Morning Edition. “It’s more transmissible than the alpha variant, so we need to just do all we can to prevent as many infections as we can and do what we can do to reduce the spread.”

Coronavirus Infections Expected Among The Vaccinated

Vaccine Efficacy Versus Delta Variant: Real World Data (COVID 19 Update 129)

As part of his argument that the COVID-19 vaccines dont work against delta, McCullough claimed that 42% of 90,000 proven delta cases in the U.K. have been vaccinated.

We asked him for the source of this statement, and he told us it came from the U.K. governments technical briefing on the variants from June 25. But the report actually shows that only 7,235 people out of 92,029 delta cases, or 7.9%, were fully vaccinated, while 58% were unvaccinated and the remainder were partially vaccinated or did not have vaccination information. By inaccurately citing 42%, McCullough gives the false impression that the vaccines are failing on a wide scale against delta.

More important, experts say it can be misleading to look at these kinds of percentages without the larger context. Thats because no vaccine is 100% effective. So as vaccination rates go up, more and more of the people who get COVID-19 will have been immunized, but fewer total people will get the disease.

As more folks get #vaccinated, the % of folks who get sick with #COVID19& happen to be vaccinated will increase. This is expected, explainedMaia Majumder, a computational epidemiologist at Boston Childrens Hospital, on Twitter. t doesnt mean that #vaccines arent working rather, it reflects the realities of probability.

The U.K. and Israel have some of the highest vaccination rates in the world, so their data can be easy to misinterpret.

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Pfizer Vaccine Very Effective Against Delta Variant In Adolescents In Israel

A vial of the Pfizer vaccine against the coronavirus disease is seen as medical staff are vaccinated at Sheba Medical Center in Ramat Gan, Israel December 19, 2020. REUTERS/Amir Cohen

JERUSALEM, Oct 21 – The Pfizer/BioNTech COVID-19 vaccine is highly effective at preventing infection and symptomatic disease from the Delta variant among 12- to 18-year-olds, research conducted in Israel shows.

The findings, published in the New England Journal of Medicine, will likely provide further reassurance the shot is effective against the variant among younger people as the U.S. drug watchdog considers authorising use of the vaccine on children as young as five.

The study found the estimated vaccine effectiveness against documented COVID-19 infection in adolescents was 90%, and 93% against symptomatic COVID-19, on days seven to 21 after the second dose.

Israel’s Clalit health maintenance organisation and Harvard University researchers reviewed data from 94,354 vaccine recipients aged 12 to 18 who were matched with an identical number of unvaccinated adolescents from the same age group.

The research was conducted between June and September, when the Delta variant was the main strain in Israel.

In a statement late on Wednesday, Clalit said the study was one of the largest peer-reviewed evaluations conducted among the age group of the effectiveness of the vaccine against the Delta variant.

A panel of advisers to the FDA is expected to weigh in on data on young children later this month.

Vaccination Reduces The Risk

Some good news from this study is that vaccination, both partial and complete, reduced the risk of severe disease and death from all the VOCs. During the course of the study, as vaccination numbers increased, hospitalizations, ICU admissions, and deaths decreased.

These results from Canada now add to those from studies from England, Scotland, and Singapore, all showing that Delta infection causes more severe disease. Fortunately, our currently available vaccines continue to provide good protection against severe Delta infections.

Prof. William Schaffner

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Vaccines Extremely Effective Against Covid Variants Of Concern: Canadian Study

Whether it’s Pfizer, Moderna or Astra Zeneca, the vaccines used in Canada ‘are doing exactly what they should be doing,’ including against the Delta variant

By Patricia TrebleJuly 5, 2021

People receive a dose of the COVID-19 vaccine at a mass vaccination clinic at Scotiabank Arena in Toronto on Sunday, June 27, 2021. THE CANADIAN PRESS/Cole Burston

Researchers around the world are sifting through data to determine how the leading COVID-19 vaccines are doing against the variants of concern. Now, a big pre-print study from Ontario suggests that the vaccines used in CanadaPfizer, Moderna and AstraZenecaare very effective against the four big variants of concern: Alpha , Beta , Gamma , and Delta .

Our findings suggest that even a single dose of these three vaccine products provides good to excellent protection against symptomatic infection and severe outcomes caused by the four currently circulating variants of concern, and that two doses are likely to provide even higher protection, the authors concluded. The studys results showed that being fully vaccinated gives a person roughly the same protection against Delta as Alpha, Beta and Gamma. The data shows that the vaccines are doing even better than previous studies suggested against the variants in terms of symptomatic infection as well as hospitalization and death.

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1st dose: 88% effective

2nd dose: n/a

Delta Variant: What We Know About The Science

Covid vaccines highly effective against hospital ...

On July 27, 2021, CDC released on the need for urgently increasing COVID-19 vaccination coverage and a recommendation for everyone in areas of substantial or high transmission to wear a mask in public indoor places, even if they are fully vaccinated. CDC issued this new guidance due to several concerning developments and newly emerging data signals.

First, a significant increase in new cases reversed what had been a steady decline since January 2021. In the days leading up to our guidance update, CDC saw a rapid and alarming rise in the COVID-19 case and hospitalization rates around the country.

  • In late June, the 7-day moving average of reported cases was around 12,000. On July 27, the 7-day moving average of cases reached over 60,000. This case rate looked more like the rate of cases we had seen before the vaccine was widely available.

Second, new data began to emerge that the Delta variant was more infectious and was leading to increased transmissibility when compared with other variants, even in some vaccinated individuals. This includes recently published data from CDC and our public health partners, unpublished surveillance data that will be publicly available in the coming weeks, information included in CDCs updated Science Brief on COVID-19 Vaccines and Vaccination, and ongoing outbreak investigations linked to the Delta variant.

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Sputnik V Vaccine Effective Against All Covid Delta Strain Variants : Research Centre Chief

Moscow: Russias Sputnik V vaccine protects against all variants of coronavirus, including the new type of the Delta strain, Alexander Gintsburg, director of the Gamaleya National Research Center of Epidemiology and Microbiology, said.Reports said three cases of infection with the new variant of the Delta strain, AY.4.2, were detected in Moscow and the Moscow Region on Monday.The Sputnik V vaccine is effective against all variants, none of the variants has become more epidemically significant than the original variant, Gintsburg said when asked whether Sputnik V would be effective against the new variant of the Delta strain.He said new Delta variants appear constantly. At the same time, there is not a single one, at least in Moscow, which, in terms of prevalence, would exceed a tenth of a per cent, Gintsburg said.Earlier, scientists in the UK reported the spread of a more contagious variant of the coronavirus than the usual Delta strain, AY.4.2.

Sputnik V And Coronavac

The makers of the Russian Sputnik V COVID-19 vaccine recently announced on Twitter that their vaccine was more effective against the delta variant than others. They added that they had submitted the data to an international peer-reviewed journal.

The company also said that it would soon be offering a booster shot specifically designed to work against the delta variant.

Until such time as the data are publicly available, it is not possible to assess the validity of these statements about the Sputnik V vaccine.

There is also little data available about how effective the Sinovac COVID-19 vaccine is against the delta variant. A recent Reuters news piece reports that over 350 doctors and medical staff in Indonesia developed COVID-19 despite receiving CoronaVac.

According to the report, Most of the workers were asymptomatic and self-isolating at home, said Badai Ismoyo, head of the health office in the district of Kudus in central Java, but dozens were in hospital with high fevers and falling oxygen saturation levels.

The region is seeing high numbers of infections, which experts believe are mostly due to the delta variant. Given the Reuters report, it is clear that more research is needed to establish exactly how well CoronaVac can protect from severe COVID-19 due to the delta variant.

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