- COVID-19 vaccines may be less effective against a more infectious version of the coronavirus found for the first time in South Africa.
- New research shows that the mutated strain may escape the antibodies developed in response to vaccination or infection with the original version of the coronavirus.
- But Pfizer said it can update its photos to combat new variants in just six weeks.
- Visit the Business Insider home page for more stories.
At first, there was little evidence to suggest that the COVID-19 vaccines would not work against the mutant and more infectious versions of the virus that have emerged in recent months.
But preliminary research published this week suggests that a variant of coronavirus detected in South Africa in December may partially escape the defenses that vaccines build in our bodies’ immune systems.
The research has not yet been peer-reviewed, but suggests that the variant, known as 501Y.V2, may escape the antibodies developed in response to vaccination or infection with the original version of the virus. This may mean that existing vaccines will not provide as much protection and people who have already been infected with the original version of the virus can be reinfected with the new strain.
Penny Moore, a researcher at the National Institute of Communicable Diseases in South Africa and co-author of the new study, said during a webinar on Monday that compelling data shows that mutations in 501.Y.V2 are “problematic”.
His group’s research found that in half of the samples studied in the laboratory, antibodies in the blood of people who recovered from COVID-19 failed to stop the variant.
“Based on Penny’s data, the vaccine is likely to be a little less effective, but we don’t know how much less effective,” said David Montefiori, a virologist at Duke University Medical Center who was not involved in the study. CNN.
The variant can avoid our body’s defenses
Stephen Craib, who has recovered from COVID-19, makes a blood donation in London.
Kirsty O’Connor / PA Images / Getty Images
Antibodies are protective proteins that our immune system generates when it detects a foreign substance, or antigen, in the body. These proteins are generated during an infection and are what a vaccine causes the body to build to prevent disease.
In general, antibodies fight infections by learning to recognize a virus and signaling to the immune system that it must be destroyed. They do this by connecting with the attacker until he is eliminated. But if a virus is different enough from others to escape the existing antibody search and destruction mechanisms, it can continue to wreak havoc.
The South African researchers decided to see if the antibodies developed in response to the original version of the coronavirus work to protect people from the new variant. They used blood samples from 44 patients who recovered from COVID-19 before variant 501.Y.V2 was detected.
Scientists exposed the blood to the new variant and found that antibodies in half of the samples were powerless against the strain. The antibodies in the other half of the samples showed a weakened response.
These results “may herald reduced effectiveness” of existing vaccines, the team wrote. They also warned that people who caught the original coronavirus could be at risk of new infections by variants such as 501.Y.V2.
In addition, Moore’s group found that three types of monoclonal antibodies – antibodies made in the laboratory designed to attack the coronavirus – were ineffective against the variant. Doctors have used monoclonal antibodies to treat patients; the Food and Drug Administration has authorized two such treatments.
Scientists work at a monoclonal antibody laboratory factory in Buenos Aires, Argentina, on August 14, 2020.
Juan Mabromata / AFP / Getty Images
Still, Moore said more data is needed to draw firm conclusions about how the variant interacts with antibodies within the body, especially among people who have been vaccinated. The research also did not look at other elements of the immune system, such as B cells, which play a critical role in the development of new antibodies.
Nathan Grubaugh, an epidemiologist at the Yale School of Public Health, said it is difficult to say how laboratory tests translate into reality in the body. A 90% reduction in protection during a laboratory test “can still mean complete protection for a human,” he told Insider.
As the virus mutates, vaccines may need to evolve
A nurse holds a vial of the Pfizer-BioNTech coronavirus vaccine.
Vincent Kalut / Photonews via Getty Images
The 501Y.V2 variant has a particular mutation in its spike protein – the part the virus uses to invade cells – that “has been shown to reduce antibody recognition” among people who have had a previous infection or vaccination, according to François Balloux, the director of University College London Genetics Institute.
Other mutations in the spike protein contribute to the increased infectivity of 501.Y.V2, the South African researchers said. This could explain why the country has been so hit since November. In the past two months, the number of new coronavirus cases per day in South Africa has increased fivefold, from an average of 2,300 to 13,000. It reached a record of almost 22,000 cases on January 8, and the country’s test positivity rate doubled in December. By the end of 2020, 501.Y.V2 had replaced almost all other versions of the coronavirus in South Africa.
It has spread to at least 20 countries.
Other variants, like the one found in the UK, have similar mutations in their peak protein. But a preliminary study by Pfizer-BioNTech found that the company’s coronavirus vaccine is effective against this variant.
Jesse Bloom, a biochemist at the Fred Hutch Institute in Seattle, said in a statement that he is “optimistic that current vaccines will remain quite useful”, although he added that as the coronavirus continues to evolve, “it may eventually be necessary to update the vaccines. “
An updated vaccine could be ‘quickly deployed’
Vaccination information for Moderna COVID-19 held at the Research Centers of America in Hollywood, Florida.
CHANDAN KHANNA / AFP photo via Getty Images
All viruses mutate. Most mutations are irrelevant, but occasionally one seems to compromise the immunity that people have acquired from a previous vaccination or infection. The flu, for example, changes rapidly, which is why we have to get a new flu vaccine every year and because flu vaccines are not 100% effective.
The coronavirus mutates more slowly than the flu. That’s why Trevor Bedford, a virologist at Fred Hutch, foreseen in April, that “the virus will take a few years to mutate enough to significantly prevent a vaccine”. But Bedford did not know at the time how much the virus would proliferate and how high the number of cases would increase; the more likely a virus is to spread (and therefore replicate), the greater the likelihood of mutations.
On Wednesday, Bedford tweeted that “the emerging situation can be addressed through an upcoming vaccine update.”
Pfizer’s partner BioNTech said it could produce a new vaccine for a variant of COVID-19 in about six weeks. Tal Zaks, chief medical officer at Moderna, said his company’s process will also be fast.
“I think our technology is very suitable for quickly deploying a vaccine based on the new variant,” said Zaks in a recent presentation at the JP Morgan Healthcare Conference.
That’s because these mRNA vaccines do not contain dead versions of the virus, but genetic instructions for the body to produce one of the virus’s signature proteins internally, thus triggering an immune response. Adjusting these instructions is an easy change.
The decision to approve a modified vaccine would then rest with the regulators.
Immunity to a virus is not all or nothing
Nurse Beth Sum receives the COVID-19 vaccination at the University of Louisville Hospital in Kentucky.
Jon Cherry / Getty Images
Even if the variant reduces the functioning of current vaccines, that does not mean that protection against infection disappears completely, experts say.
“We often talk about immunity as a kind of all-or-nothing, but it’s not,” Jennie Lavine, a postdoctoral researcher in biology at Emory University, told Insider.
The ideal level of protection is sterilizing immunity – when “we have immunity so good in the right places that the virus cannot even replicate if it enters,” said Lavine.
But there is a lot of compromise between that and zero immunity. For example, Lavine said, “the virus may be able to replicate, maybe cause mild pathology, maybe spread for a day or two instead of five or six days.”
She added: “The chances that the new variant will take us from sterilizing immunity to a lack of immunity are really unlikely.”
It also helps that existing vaccines are highly effective against the original virus.
“The Pfizer and Moderna vaccines are 95% effective – an extraordinary level of effectiveness,” Montefiori told CNN. “If it drops to 90, 80, 70% effectiveness, it is still very, very good and is likely to have a big impact on the pandemic.”
Catherine Schuster-Bruce and Aria Bendix contributed to the account of this story.