The Covid-19 vaccine developed by AstraZeneca and the University of Oxford protected people against a new, more contagious coronavirus variant at similar levels to the protection it offered against other lineages of the virus, Oxford researchers said in a paper released on Friday.
The paper, which has not yet been peer-reviewed, said that the vaccine had 74.6 percent efficacy against the new variant, which was first detected in Britain and is known as B.1.1.7. That was similar, though slightly lower, than its efficacy against other lineages of the virus.
The encouraging, albeit preliminary, findings suggest that all five of the leading vaccines may offer at least some protection against new variants of the virus spreading around the globe. Still, the mounting evidence suggests that mutant viruses can diminish the efficacy of vaccines, increasing the pressure on countries to quickly vaccinate their populations and outrace the variants taking hold across the globe.
In clinical trials, the AstraZeneca-Oxford vaccine protected all participants against severe illness or death.
The Oxford scientists behind the vaccine took weekly swabs from the nose and throat of participants enrolled in their clinical trial in Britain. To determine the vaccine’s efficacy against the new variant, they sequenced the viral particles from several hundred swabs between Oct. 1 and Jan 14, a period when the new variant was known to be present in Britain.
The vaccine had 84 percent efficacy against other lineages of the virus, compared to 74.6 percent against the new variant, though the small sample sizes created a broad range of estimates.
Andrew Pollard, the lead investigator of the Oxford vaccine trial, said in a statement that data from the research released on Friday “indicate that the vaccine not only protects against the original pandemic virus, but also protects against the novel variant, B.1.1.7, which caused the surge in disease from the end of 2020 across the U.K.”
The researchers also studied blood samples from clinical trial participants who had been vaccinated, and they determined that the variant may be more adept at dodging antibodies generated by the vaccine.
The variant first detected in Britain has since been reported in more than 70 other countries. Public Health England has estimated that the variant’s rate of infection is 25 percent to 40 percent higher than that of other forms of the coronavirus.
Preliminary data from lab tests of the vaccines from Pfizer and Moderna suggest that they offer good protection against the B.1.1.7 variant. Novavax, which sequenced testing samples from its clinical trial participants in Britain while the variant was circulating widely there, found that its vaccine was highly effective against the B.1.1.7 variant.
Currently more than 150 million people — almost half the population — are eligible to be vaccinated. But each state makes the final decision about who goes first. The nation’s 21 million health care workers and three million residents of long-term care facilities were the first to qualify. In mid-January, federal officials urged all states to open up eligibility to everyone 65 and older and to adults of any age with medical conditions that put them at high risk of becoming seriously ill or dying from Covid-19. Adults in the general population are at the back of the line. If federal and state health officials can clear up bottlenecks in vaccine distribution, everyone 16 and older will become eligible as early as this spring or early summer. The vaccine hasn’t been approved in children, although studies are underway. It may be months before a vaccine is available for anyone under the age of 16. Go to your state health website for up-to-date information on vaccination policies in your area
You should not have to pay anything out of pocket to get the vaccine, although you will be asked for insurance information. If you don’t have insurance, you should still be given the vaccine at no charge. Congress passed legislation this spring that bars insurers from applying any cost sharing, such as a co-payment or deductible. It layered on additional protections barring pharmacies, doctors and hospitals from billing patients, including those who are uninsured. Even so, health experts do worry that patients might stumble into loopholes that leave them vulnerable to surprise bills. This could happen to those who are charged a doctor visit fee along with their vaccine, or Americans who have certain types of health coverage that do not fall under the new rules. If you get your vaccine from a doctor’s office or urgent care clinic, talk to them about potential hidden charges. To be sure you won’t get a surprise bill, the best bet is to get your vaccine at a health department vaccination site or a local pharmacy once the shots become more widely available.
That is to be determined. It’s possible that Covid-19 vaccinations will become an annual event, just like the flu shot. Or it may be that the benefits of the vaccine last longer than a year. We have to wait to see how durable the protection from the vaccines is. To determine this, researchers are going to be tracking vaccinated people to look for “breakthrough cases” — those people who get sick with Covid-19 despite vaccination. That is a sign of weakening protection and will give researchers clues about how long the vaccine lasts. They will also be monitoring levels of antibodies and T cells in the blood of vaccinated people to determine whether and when a booster shot might be needed. It’s conceivable that people may need boosters every few months, once a year or only every few years. It’s just a matter of waiting for the data.
The paper released on Friday did not address the AstraZeneca vaccine’s protective power against another fast-spreading coronavirus variant, known as B.1.351, that was first identified in South Africa. Researchers are conducting similar lab tests to try to measure the effect of that variant on the vaccine’s potency.
AstraZeneca’s vaccine has been authorized in nearly 50 countries around the globe but not the United States, where the Food and Drug Administration is waiting on data from a clinical trial that enrolled more than 30,000 participants, mostly Americans. Results from that study may come this month, and AstraZeneca is expected to have enough safety data to seek emergency authorization from the F.D.A. around the first week of March.
In the United States, the B.1.1.7 variant has been identified in 33 states, but the full extent of its spread is unknown because of the lack of a national surveillance program. Federal health officials have warned that it could become the dominant form of the virus in the United States by March.