The vaccine developed by the University of Oxford and AstraZeneca not only protects people from serious illness and death, but also significantly slows the transmission of the virus, according to a new study – a finding that underscores the importance of mass vaccination as a way out. the pandemic.
Researchers at the University of Oxford measured the impact on transmission by taking the participants weekly to look for signs of the virus. If no virus is present, even if someone is infected, it cannot be spread. And they found a 67 percent reduction in positive smears among the vaccinated.
The results, detailed by Oxford and AstraZeneca researchers in a manuscript that has not been peer-reviewed, showed that the vaccine could reduce transmission by nearly two-thirds.
Matt Hancock, UK Health Secretary, greeted the results on Wednesday as “absolutely fantastic.”
“We now know that the Oxford vaccine also reduces transmission and that it will help all of us get out of this pandemic,” Mr Hancock said in an interview with the BBC on Wednesday morning.
The results, he said, “should give everyone confidence that this shot works not only to protect you, but also to prevent you from passing the virus on to others.”
Some scientists, looking at the limited information released, warned that more analysis of the data was needed before such broad conclusions could be definitively formulated.
“While this would be extremely welcome news, we need more data before it can be confirmed, so it’s important that we all still follow social aloofness guidelines after we get vaccinated,” said Dr. Doug Brown, CEO of the British Immunology Association.
The Oxford and AstraZeneca researchers also found that a single dose of the vaccine was 76 percent effective in preventing Covid-19. The data was measured in the three months after the first injection was given, excluding an initial three-week period required for the protection to work.
The encouraging results support Britain’s and other countries’ strategy to prioritize providing as many first doses of vaccines as possible, aside from concerns that people will get their second doses later than originally planned.
The most recent data does not influence the discussion of whether the doses of the two vaccines approved in the United States, those of Pfizer-BioNTech and Moderna, should be further disseminated, as the data on AstraZeneca’s candidate does not can be generalized to other vaccines.
Some scientists have called on the United States to follow the lead of Britain and other countries that have chosen to delay the second dose of vaccines for up to 12 weeks. But US federal officials opposed, saying such a move would not be supported by the data from clinical trials of the two vaccines currently available across the country. Tuesday’s results could increase pressure on US health officials to delay second doses of the AstraZeneca vaccine, although it has not yet been approved by the country.
The vaccine turned out to be more effective if the interval between the two injections was longer than the originally intended four-week interval, the Oxford and AstraZeneca researchers found. Among clinical trial participants who received two doses of standard strength at least three months apart, the vaccine was 82 percent effective, compared to 55 percent effective when the doses were given less than six weeks apart.
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Answers to your vaccine questions
Currently, more than 150 million people – nearly half of the population – are eligible for vaccination. But each state makes the final decision on who goes first. The 21 million health workers and three million residents of long-term care facilities were the first to qualify. In mid-January, federal officials urged all states to qualify anyone 65 and older and adults of any age with medical conditions who 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 resolve bottlenecks in vaccine distribution, anyone 16 and older will be eligible as early as this spring or early summer. The vaccine is not approved in children, although studies are ongoing. It can take months for a vaccine to be available to someone under the age of 16. Visit your state’s health website for current information on vaccination policies in your area
You don’t 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 get the vaccine for free. Congress passed legislation this spring that prohibits insurers from applying any cost sharing, such as a personal contribution or deductible. It was layered on additional protections that prevented pharmacies, doctors and hospitals from considering patients, including those who are uninsured. Still, health experts worry that patients could get caught in loopholes that leave them vulnerable to surprise bills. This can happen to those who have to pay a doctor visit fee in addition to their vaccine, or Americans who have certain types of health coverage that aren’t covered by the new rules. If you get your vaccine from a doctor’s office or an emergency room, talk to them about possible hidden costs. To make sure you don’t get a surprise bill, it’s best to get your vaccine from a health department vaccination site or local pharmacy once the injections are more widely available.
That has yet to be determined. It’s possible that Covid-19 vaccinations will become an annual event, just like the flu shot. Or it could be that the benefits of the vaccine last for more than a year. We have to wait and see how durable the protection against the vaccines is. To determine this, researchers will follow vaccinated people looking for “breakthrough cases” – those people who fall ill with Covid-19 despite vaccination. This is a sign of weakening protection and gives researchers clues about how long the vaccine will last. They will also monitor the levels of antibodies and T cells in the blood of vaccinated people to determine if and when a booster shot may be needed. It is conceivable that people will need boosters every few months, once a year, or just every few years. It’s just a matter of waiting for the data.
A vaccination strategy in which doses are delayed by three months “could be optimal for the introduction of a pandemic vaccine when supplies are limited in the short term,” the researchers wrote.
The recently released study builds on data released late last year that showed the vaccine was 62 percent effective when given as two standard doses. In those initial findings, the vaccine efficacy was much higher, at 90 percent, when the first dose of the vaccine was given at half strength.
Researchers at Oxford and AstraZeneca initially attributed the different efficacy levels to the lower strength of the starting dose. But gradually they came to a different conclusion: the amount of time between doses was the most likely explanation.
In the United States, the Food and Drug Administration is awaiting data from a clinical trial involving about 30,000 participants, mostly Americans. The results of that study are expected later this month.
The study is expected to provide AstraZeneca with sufficient safety data to request authorization to provide the vaccine for emergencies by early March.
The United States has agreed to buy 300 million doses of AstraZeneca’s vaccine, but neither the company nor the federal government have said when and in what quantities those doses will be available after the vaccine is approved.