Will you be immune to COVID-19 for 3 months after recovery? It’s not clear

That’s the question everyone wants to answer: how long are you protected from catching COVID-19 after recovering from a new coronavirus? What does that really mean?

Last week, the Centers for Disease Control and Prevention Online quarantine guidelines Those who have recovered from COVID-19 say they do not need to be quarantined or retested for up to three months, but officials said in a statement to CNN on Friday that they would not be affected by reinfection. did.

“People who test positive for COVID-19 do not need to be quarantined or retested for up to 3 months unless they reappear,” said CDC Guidance.

A CDC spokesperson said, “This guidance is based on the latest science on COVID-19 and can remain positive for up to 3 months after diagnosis without infecting others.” ..

But “this science doesn’t mean that people are immune to reinfection with SARS-CoV-2, a virus that causes COVID-19 within three months of infection. According to a CDC statement, The latest data show symptoms of COVID-19 and suggest that they do not need to be retested 3 months after the first infection unless the symptoms are related to another disease ..

“I think it’s an incredibly sticky ticket gate, as Britain says,” William Schaffner, a professor of preventive medicine and infectious diseases at Vanderbilt University School of Medicine in Nashville, who was not involved in the CDC guidance. Said the doctor.

“We think antibodies correlate with protection, but we don’t really know that yet,” Schaffner said.

According to Schaffner, practical applications are far from over. For example, can anyone with an antibody ever date or stop wearing a mask? Absolutely not, he stressed.

Immunity 101

Our adaptive immune system is designed to target specific previously recognized invaders and contains two major cellular components, B cells and T cells. Previous research in immunity has focused primarily on B cells, a type of white blood cell programmed to find and bind foreign invaders.

When B cells attach to a virus, such as the novel coronavirus that causes COVID-19, they “copy themselves to produce antibodies, and ultimately a large neutralizing agent for that particular invader. Create a” CNN medical correspondent Dr. Sanjay Gupta said in an explanation about viral immunity..

“Unfortunately, several recent studies have shown that antibodies to this particular coronavirus can disappear fairly quickly, especially in people who have experienced mild cases of COVID-19. Gupta says.”

Preprinted paper released in July (meaning not published in peer-reviewed journal) Discovered that antibody response appears to decline 20-30 days after COVID-19 symptoms Will be displayed first.

“This study has important implications for examining the persistence of SARS-CoV-2 reinfection protection and vaccine protection,” the researchers wrote.

In June, Small study People who are infected with coronavirus but have no symptoms have discovered that their immune response to the virus may be weak.

The study found that antibody levels in a group of approximately 30 asymptomatic COVID-19 patients were significantly lower than those seen in patients with mild symptoms.

In early July, a Spanish government study found that only 5% of people in Spain have coronavirus antibodies, which weakens their immunity to coronaviruses in the weeks ahead, amid concerns about development. it was done. The results show that 95% of the Spanish population is susceptible to the virus.

This means that the perceived immunity “is incomplete and transient, and may then disappear.” At the then press conference, said Dr Raquel Yotti, head of the Carlos III Health Institute. Laboratories are the leading government agencies that lead research.

Expect T cell response

Science hopes that COVID-19 will also trigger an immune response from T cells, another arm of the adaptive immune system. One type, called memory T cells, helps the body remember a particular intruder when it comes back.

Recent studies have found such memory T cells in people infected with SARS-CoV-2, a new coronavirus that causes a disease called COVID-19. The finding leads to the speculation that some people may get mild cases of COVID-19 as T cells are responsive to exposure to similar coronaviruses they have previously encountered.

The virus SARS-CoV-2 belongs to a large family of coronaviruses, six of which were previously known to infect humans. Two are deadly. SARS-CoV-1, the virus that caused the outbreak of severe acute respiratory syndrome (SARS) that ended in 2004. MERS-CoV, a virus that causes Middle East respiratory syndrome (MERS).

The other four cause colds and circulate widely every year, so many people may already be exposed to one of the so-called “cousins” of the new coronavirus.

“They have been studied, and after catching a cold, you develop antibodies to that particular human strain of coronavirus, and you know that you are protected, but protection begins to weaken after about a year.” It turned out,” Schaffner said.

“Don’t you wonder how much protection we got from this virus when COVID-19 came out? And how long does it last if you get the protection?” he added. “We still don’t know its behaviour.”

Continue the course

Another page of the CDC site updated in June It refers to the uncertainty surrounding the role of antibodies in future infectious diseases.

“Having antibodies to the virus that causes COVID-19 may provide protection from re-infection with the virus. If so, we may provide how much protection the antibody may provide I don’t know, or how long this protection may last,” says the CDC.

Until science had a better understanding of the duration of immunity, Schaffner recommended continuing the course of what is known to work, such as hand washing, social distance, crowd avoidance, and mask wear.

“You don’t look around why you don’t wear a mask, you just wear it. You get used to it,” Schaffner said. “We all want to come together and see our solidarity.”

Editor’s Note: This article has been updated to include comments from the CDC clarifying quarantine guidance.