Fact Check: Do COVID Vaccines Protect Against the Delta Variant? | News and events in Germany and around the world | DW

In the UK, at least 259 people have died after contracting the delta variant of COVID-19. Of those, 116 people have been fully vaccinated, according to the latest data from Public Health England (PHE), an agency of the UK Department of Health. This is why one of the biggest questions on the internet today is: is a vaccination still protect against the delta variant?

The good news first: Yes, a vaccination always protects you.

Why is there a residual risk despite the double vaccination?

None of the vaccines that have been approved so far offer 100% protection against coronavirus infection – studies have shown since their introduction.

Vaccinated people, especially those with pre-existing illnesses, are still at low risk of getting infected – and in the worst case, of dying. However, the current death rate in the UK remains low, despite rising infection rates.

One of Germany’s top virologists, Christian Drosten, said in a Coronavirus Update podcast in June that there were “cases where double-vaccinated people also die.” He suggested that experts carefully consider the exact cause of death and how the diagnosis was made.

The high proportion of people vaccinated among the dead is likely due to the fact that around half of the population is now fully immune, combined with the fact that the number of deaths overall is declining.

Additionally, according to PHE data, 116 of the 118 people who died were over the age of 50.

Peggy Riese, scientist at the Helmholtz Center for Infection Research (HZI), explained the scenario using a real-life example. “If 100% of a population is vaccinated, then a few vaccinated people also die,” she told DW. She said that doesn’t mean the vaccine isn’t safe, just that it doesn’t offer 100% protection.

In addition, a small number of vaccinated people could die if their inoculations were ineffective due to the presence of immunosuppressants, for example, in those who have had transplants, as recently stated by Georg Behrens, professor at the clinic of rheumatology and immunology of the faculty of medicine of Hanover. DW.

Behrens said the effect of the vaccination wears off after a few months as well. “Some people can still suffer from serious illness in unfortunate constellations,” he said. Vaccines protect very well, but Behrens also warned that no vaccine could ever provide 100% protection.

A study by the UK’s Medical Research Council (MRC) Biostatistics Unit (BSI) at the University of Cambridge suggests that vaccinations have prevented an estimated 7.2 million infections and 27,000 deaths alone. in England. “The number of infections and deaths averted by the vaccination program is not only surprisingly high, but increases exponentially during the vaccination program,” said Paul Birrell, one of the scientists involved in the study.

Good protection after full vaccination

All experts interviewed by DW expressed confidence in the efficacy of the vaccines against the delta variant. “The vaccinations are fantastic,” said virologist Friedemann Weber of the University of Giessen, for example. “The immune response in vaccinated people who have received both doses and are waiting accordingly, is higher on average, or as high as for people who have received an immune response after infection,” he explained.

Scientific findings support the expert’s assessment.

According to a recent study published in the journal Nature, a double vaccination of BioNTech-Pfizer continues to protect strongly against the delta variant. However, new data from Israel rates the protective efficacy against the delta variant as slightly lower than previous variations.

Israel’s health department announced in a press release that the efficacy of BioNTech-Pfizer vaccine against the delta variant in terms of completely preventing infection has fallen to 64%.

Nevertheless, vaccination continues to protect 93% of individuals from serious infection with hospitalization. It is not transparent how the Israeli health department obtained the data. So far, the press service has not provided more detailed information on the procedure in the study despite DW’s request.

Moderna’s COVID-19 vaccine also showed high protection against the delta variant, according to an unpaired Canadian study from early July. The study said the Moderna vaccine was 72% effective from 14 days after the first dose. The study was published before sufficient data could be gathered on protection after two doses.

Vaccine maker Johnson & Johnson (J&J) claims its vaccine produced a strong immune response eight months after vaccination. J&J presented its interim results from a 20-person study that shows its vaccine produces antibodies against the delta variant. However, no clear amount of efficacy has been shown so far.

Published studies on vaccine protection against the delta mutation are highly variable, as shown by a comparison presented in the Financial Time.

Will a “booster” become necessary?

Georg Behrens of Hanover Medical School stressed that it was necessary to take into account when Israelis infected with the delta variant had been vaccinated. The first vaccines were given in December 2020, and Behrens said the effect of the initial inoculation may slowly wear off, making another dose necessary.

The makers of the BioNTech-Pfizer vaccine have also pointed in this direction in their latest press release. In order to maintain efficacy, they seek approval for a third dose of vaccination six months after the second vaccination.

Are mRNA vaccines better than vector vaccines?

Earlier data from the UK had indicated a slightly higher efficacy of the two mRNA vaccines (BioNTech-Pfizer and Moderna) against hospitalization than Israeli data showed: According to a PHE study, one dose of the BioNTech-Pfizer vaccine is believed to prevent serious illness. with hospitalization due to the delta variant up to 94%, with protection reaching 96% after the second dose.

The PHE study said that people vaccinated with AstraZeneca are 71% protected against a serious course of the disease with hospitalization after the first vaccination and 92% after the second.

According to another study published by PHE, vaccines also protect against symptomatic reactions to possible infection with the delta variant. In this one, BioNTech-Pfizer shows 36% protection against symptomatic illnesses after the first dose and 88% after the second. AstraZeneca showed 30% protection after the first dose and 67% after the second.

The results of the study indicate that the delta variant is more resistant to vaccines, but that full vaccination continues to provide strong protection even against this variant.

What is the probability that the variants are more dangerous?

Variants appear when the virus mutates. “New variants are likely to appear for a while,” said virologist Friedemann Weber, adding that new variants continue to appear until the majority of the population has been vaccinated. Yet the virologist does not assume that vaccinations will suddenly become ineffective.

Fact Check: Did COVID Vaccines Cause the Delta Variant?

Behrens said it’s impossible to accurately predict whether more dangerous variants will emerge, but said there are still many less dangerous mutations that do not prevail.

He said the best protection in either case is vaccination, because the more people are vaccinated, the higher the population’s immunity and the lower the infection rate.

Peggy Riese agreed, saying the coronavirus mutates more frequently than, for example, the measles virus – but less often than the influenza virus. It is therefore neither a virus which mutates particularly quickly, nor a virus which mutates very slowly.

Do we need new vaccines?

So far, vaccines have been shown to be very effective against all of the mutations of concern. Riese said vaccines will need to be adjusted when they lose their effectiveness. Still, one should not be too hasty, she warned: “A vaccine is not developed so quickly either. If a mutant is created every quarter, we can no longer keep up with the development of a vaccine. . “

It is also possible that a vaccine suitable for a particular variant will become obsolete when that strain mutates again.

Virologist Weber sees it a little differently. “You should adapt the vaccines right away,” he said, adding that the main studies that need to be done before approval for use take a long time.

According to vaccine maker BioNTech-Pfizer, it is already developing a vaccine specifically designed to fight the delta variant. The first clinical studies should start in August.

Researchers at the famous Charite Hospital in Berlin also assume that COVID-19 vaccinations will need to be checked regularly during the pandemic and adjusted if necessary. Right now, the virus is growing rapidly because there are many infections around the world, so the virus can grow faster, according to a press release.

“Based on the home flu coronavirus development rates, we assume that SARS-CoV-2 will also change more slowly once the infection process subsides, that is, after a much of the world’s population will have built up immune protection either through the disease itself or through vaccination, ”explained Jan Felix Drexler of the Charity Institute of Virology.

As soon as the situation stabilizes, he said, the vaccinations can likely be used for longer periods of time.