Can vaccinated people still spread the coronavirus? Should they wear masks?

ANGELS – It may sound simple: Get the COVID-19 vaccine and now you are protected from the disease. But can you still get infected and transmit the coronavirus, which has killed more than 300,000 Americans, even after being vaccinated?

Last week, Pfizer and BioNTech’s first vaccine received emergency use authorization from the United States Food and Drug Administration, and shipments to hospitals across the country quickly began. The first 3 million vaccines were strictly rationed to frontline health workers and elderly patients.

A key FDA advisory committee voted Thursday in favor of approving Moderna’s COVID-19 vaccine for emergency use, meaning it could become the second vaccine to be approved by the agency and to be distributed throughout the United States.

The Pfizer and Moderna vaccines have shown promising results in their phase three trials with 90-95% efficacy.

“What this efficacy means is protection against COVID disease – which could be mild, moderate, and severe illness. The trials were primarily designed to see if these vaccines protect against disease,” Dr. William Moss, professor at the John Hopkins Bloomberg School of Public Health and an executive director of the International Vaccine Access Center, told FOX TV Stations. “The fact that we have had a vaccine for a year and that we have such protective vaccines is simply amazing.”

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The results of the vaccine trials came from 30,000 to 45,000 volunteers in each study. The researchers tested whether the participants showed signs or symptoms of COVID-19 after the vaccination, then tested the individuals with a nasal swab to see if they could confirm that the individual was infected with the coronavirus.

While trials have tracked the number of people with COVID-19 after taking the vaccine, questions remain as to whether the vaccines offer protection against infection with the coronavirus.

Can vaccinated people get infected with the coronavirus?

“There are a number of unanswered questions,” Moss said.

For example, could vaccinated people still be infected silently, spreading the virus to others without knowing it?

“The short answer is we don’t know yet,” Moss said. “What we can assume is that if these vaccines protect against disease, that individuals, if infected, will have a lower level of virus.”

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Moderna has found a clue that his vaccine may prevent asymptomatic infection. Study participants had their noses swabbed before the second dose of the vaccine or placebo. At that time, swabs from 14 vaccines and 38 placebo recipients showed signs of asymptomatic infection, said Dr Jacqueline Miller of Moderna.

Meanwhile, a study published in November suggested that some people may generate a level of COVID-19 ‘immune memory’ that may offer some protection against the coronavirus after infection, even after six to eight months.

“Most people have been building immune memory for at least six months or more and it looks like a type of immune memory that is probably able to prevent most people from getting serious illness again,” Dr. Shane Crotty, researcher in immunology and vaccine co-author of the study, said.

Another vaccine trial from AstraZeneca, which announced some of its test results in November, used different approaches to inoculate the people who participated, and its results suggest that a vaccine could prevent some infections.

“They could see in some preliminary scans from their phase three trial that the vaccine appears to prevent asymptomatic infection – that infection without symptoms – and that most likely means that these people cannot transmit the virus. This is what they do. have evidence of that, ”Moss said.

The efficacy of AstraZeneca’s vaccine candidate averaged around 70%, according to the company.

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But the results from AstraZeneca and Moderna still do not indicate – with certainty – whether a vaccinated individual could pass the virus on to others.

“We don’t yet know if these vaccines actually prevent what we call an asymptomatic infection, an infection without symptoms, and if they actually stop someone from passing the virus to another person,” Moss said.

Moss said this is a point that will need to be further explored in the future, and the hope is that more will be known in the months to come, as vaccine trials continue to progress.

Should people still wear masks after being vaccinated?

While there is a chance that those vaccinated can still spread the coronavirus asymptomatically, the need for masks will not diminish as the vaccines are rolled out.

In essence, people who are vaccinated could potentially endanger unvaccinated people, Moss acknowledged.

“People will continue to need to wear masks, to physically distance themselves, to wash their hands frequently, to avoid large gatherings, certainly in the months to come until a large part of the population American be vaccinated, ”Moss said. “We are going to have to continue with these basic public health measures, even if these vaccines are put in place.”

Dr Jason McKnight, a primary care physician at Texas A&M University, echoed Moss’ advice, stressing that wearing a mask is not only a barrier against COVID-19, but also against other viruses.

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“Continuing to wear a mask can help prevent the spread of other respiratory illnesses, which can help avoid overwhelming the health care system, as we are already seeing during the pandemic,” McKnight said.

The U.S. Centers for Disease Control and Prevention still maintains that wearing a mask, social distancing at least six feet away, and washing your hands are important steps in slowing the spread of the virus.

While the vaccine’s 95% effectiveness seems reassuring, it still means the vaccine didn’t work for 5% of people, suggesting that following CDC guidelines is even more imperative.

“The vaccine is not 100% effective,” Moss said. “So until we get this pandemic under control, until transmission is reduced, there are still people who have been vaccinated who can still get COVID-19.”

What side effects can be expected from vaccines?

Moss noted that some normal side effects are expected after vaccination.

“It is our body’s immune system that reacts to the vaccine. These are common and we have seen them with the Pfizer and Moderna vaccine – pain at the sight from the injection, muscle pain, headache, joint pain, some people will have a fever. These are all the expected side effects of the vaccine. “

According to History of Vaccines, an educational resource provided by the College of Physicians of Philadelphia, most side effects from vaccinations are mild.

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Common side effects include pain or swelling at the injection site, fever, rash, and pain. But in rare cases, the side effects can be serious, such as a life-threatening allergic reaction.

Side effects reported in the Pfizer and Moderna vaccine trials are in line with common adverse events.

However, some people have suffered from allergic reactions after receiving Pfizer’s COVID-19 vaccine. British regulators last week said two healthcare workers who had received the Pfizer coronavirus vaccine had severe allergic reactions.

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Meanwhile, a healthcare worker in Alaska who was identified as a middle-aged woman had an allergic reaction including redness and shortness of breath within 10 minutes of receiving Pfizer’s first two-dose vaccine. Tuesday.

“We still don’t know which component of the Pfizer vaccine is really causing this anaphylactic reaction – this severe allergic reaction that we’ve seen – at the moment there are no plans to delay or change the way we will vaccinate,” said Moss. “We will learn more about what in the vaccine causes these allergic reactions and if we will also see them with the Moderna vaccine.”

Will vaccines end the pandemic?

Going forward, Moss says researchers want to continue learning more about the potential impacts of vaccines.

“We need to better understand how long the protection lasts, how long the protection lasts, and that we will only learn if we continue to track trial participants and observe people who are vaccinated,” Moss said. “We’re going to need to learn how these vaccines work and if they are safe for pregnant women and young children so that these people can get vaccinated.”

But Moss says there is hope.

“We hope we can survive this pandemic. It will take time. There will be bumps until we have everyone who needs or wants to be vaccinated in the United States, but we are seeing a light. But it means that we really need to be very careful and protect ourselves and the people around us with the other basic public health measures so that we can get to that point in the vaccine where we can start to get our life back to normal, “Says Moss.

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Moss noted that researchers will need to learn more about how to vaccinate large numbers of people in the United States, because nothing has ever been done on such a large scale.

Moss said the message around vaccines is also critical to widespread adoption.

“There are going to be rumors, there will be misinformation and misinformation, and we have to be prepared to send the right messages – the right information about these vaccines,” Moss said.

The Associated Press contributed to this story.