How bad is it to get a booster while you have a COVID?

Last week our colleague MedPage today I got her booster shot. She was ready for the side effects of the vaccine-malaise, pain, and perhaps even fever. What she didn’t expect was a day-long illness and a positive COVID-19 rapid antigen test.

In retrospect, that makes sense. She remembered ticking her throat on the day of the booster shot, but thought it was her body’s reaction to a busy weekend. After deciding to take the test, she learned that she was in contact with someone who tested positive.

Thankfully, it looked like a mild infection. But what if I get a booster shot when someone is already infected with SARS-CoV-2? MedPage today I consulted with an infectious disease and microbiology expert to find out.

Dr. Ameshua Dalha, MD, an infectious disease specialist at the Johns Hopkins School of Public, said that if you inadvertently get infected with the virus just before or after the boost, the infection can cause symptoms, but it can interfere with the effectiveness of the booster. States low. Baltimore health.

“I don’t think it will have a big impact, except that you may be fighting more symptoms from the vaccine and the infection you have at the same time,” he said. “May be more uncomfortable than usual.”

In fact, the chances of getting infected with SARS-CoV-2 are about the same as without a booster up to 6 days after taking a booster shot. JAMA Internal Medicine.. “If you just got the booster a day ago, you shouldn’t have it at all,” said Dr. Benjaminten Oever, a professor of microbiology at the NYU Grossman School of Medicine.

When going to booster shots, vaccination site staff may ask if you are experiencing COVID-19 symptoms. This is not because the infection interacts with the booster, but because it protects everyone at the vaccination site. However, Simone Wildes, MD, an infectious disease specialist at South Shore Health in South Weymouth, Massachusetts, said that infections near or around the time of vaccination are not uncommon and not particularly harmful, but wait until antibodies are released. Said it made sense. After infection, the level drops and boosters occur.

The CDC initially recommended waiting 90 days after infection for vaccination. But then she said the guidelines were changed to reduce the chances of completely skipping vaccines and boosters after someone waited. According to the updated guidelines “People with symptomatic COVID-19 need to wait for vaccination until they recover from the disease and meet the criteria for discontinuing quarantine.”

The immune response to a vaccine containing boosters is a different process than the immune response to the virus itself, even though both infections and vaccines can cause symptoms that occur in response to the virus.

Immune response to mRNA vaccine

After receiving the initial inoculation, some cells in the body pick up the injected mRNA and start running dozens of times compared to a software program to produce the spiked glycoproteins that characterize SARS-CoV-2. increase. Antigen-presenting cells “see this very strange-looking structure on the surface of the muscle cells in the shoulder and control the response to it. The response takes time,” he said.

“The antigen-presenting cells teach the immune system how to recognize this foreign protein, which in this case is a spike,” he added, within a few weeks of a stronger immune response after vaccination.

The mRNA that enters your arm also teaches the immune system to recognize foreign spike proteins in muscle cells via immunoglobulin G, but not in mucosa that use immunoglobulin A. Without this mucosal immunity, tenOever explained, SARS-CoV-2 can infect the upper respiratory tract after exposure to the virus, but most often in vaccinated people. It cannot be infected any further.

Immune response to SARS-CoV-2

When infected before and after boosters, not only is mucosal immunity lost, but the learning process benefits that immune cells receive in the weeks following vaccination are also lost. “The longer it takes to see the actual virus from the booster, the better you are because you have given the immune system more time to explore different spaces and ways to block the virus. “Masu,” said ten Oever.

However, if you happen to be infected and recover, the immune learning process is refined as follows: RNA vaccine cannot be induced.. “When infected, the virus apparently kills cells, destroys them, causes enormous confusion, and begins to lose a lot of inflammation, but it allows the immune system to recognize other components,” he said. I am saying. Nucleocapsid protein, Unlike peplomer, it is inside the virus.

How to tell the difference between the two

Fever, muscle and pain, and headache can be associated with both immune response scenarios, but the side effects of the vaccine are somewhat distinguishable from the symptoms of breakthrough infections, Adalja said.

“Upper respiratory tract symptoms will be a clue,” explained Adalja. These include sore throat, congestion, and loss of taste and smell.

“And the other side is whether it’s going to last,” he added. The side effects of boosters may last only a day or two, but prolonged illness can mean an infection.

“That’s important,” Wilds said. “If symptoms last for more than 72 hours, it is highly recommended that you contact your healthcare provider for testing, as most people’s vaccines should not exceed that point.”

Hybrid immunity

Immunity from infection is because the body builds such a strong response system after infection. High degree of protection -But even more so with vaccination.and Study at NatureResearchers have found that previously infected vaccinated people neutralize SARS-CoV-2 better than previously infected vaccinated people. A Preprint survey Israel has suggested that hybrid immunity may last longer than vaccine-induced immunization, but both may decline over time.

So how long does hybrid immunity prevent reinfection? “If [natural immunity] If it occurs in the delta variant, it may not be sufficient for the omicron variant. But again, boosters may not be enough for that, “Adalja said.

Wilds said they would not recommend a vaccine to these individuals if the natural infection alone provided sufficient immunity. “What happens is that different people have different levels of antibodies, so they are not well classified.”

What to expect

In any case, the infection that occurs before the booster shot has time to build a complete defense of the body is probably mild. Of course, this depends on other factors: age, comorbidities, and immunodeficiency. Experts say there is still the possibility of getting a serious illness or spreading the virus to others.

Essentially, breakthrough infections develop shortly before or shortly after booster shots are possible, and the resulting hybrid immunity provides some additional protection. And, like all reactions to the virus, it varies from person to person.

But the most important thing the experts emphasized is to get vaccinated in the first place and, where appropriate, boost immunity.

“Get a booster,” Wilds said. “I want to make sure that the data are clear. The double dose vaccine will not work against the Omicron mutants that are already here.”