Why health professionals say they need a vaccine even if they are infected with COVID-19

Some people who have been infected with COVID-19 may not be interested in getting vaccinated, but the growing number of evidence and warnings from other countries is It shows that innate immunity is not the answer to overcoming a pandemic.

The most vulnerable people are those who have not been infected or vaccinated before, but new studies on vaccines and variants show that people who have the virus but are not vaccinated are fully vaccinated. It has been shown to be at higher risk than people.

“The idea that you were previously infected and protected by the virus: it’s often seen that it’s not true,” said Dr. Vingputa, a doctor and professor at the Institute of Health Measurements and Evaluations at the University of Washington. I am. University of Washington. “There is no strong protection for previous infections, especially due to infections of these variants.”

Variant originated in the UK, B.1.1.7 variant, The most common cycle So far, Washington has been associated with more infections and, in some cases, more serious illnesses.

The UK variant has also been associated with the most breakthrough cases in the state so far, with 98 recorded cases of fully vaccinated individuals positive for the variant.

In the last few months, virus-positive people have essentially experienced a different COVID-19 infection than those who were infected a year ago. The virus mutates, and the more people who are not vaccinated, the more opportunities they have to change the form of the virus, and the better the mutations that avoid antibody treatment or spread faster.

Currently, the vaccines available in the United States work well against mutants, so the immune response seen in fully vaccinated people is specialized to be stronger than those previously infected with COVID-19. The house says.

Gupta said he explained this to patients, especially those who are infected with COVID-19 and believe they are immune. If the coronaviruses have not changed or evolved, their immunity may be stronger, but that is not the case.

“Antibodies developed from infections from the original virus are not very useful,” says Gupta.

He added that the vaccine produces a stronger response at the biological level.

Studies measuring antibodies in people who have previously been infected with COVID Various results, And scientists still don’t know how long innate immunity lasts.In addition, some studies show that Antibody reactions may be correlated How serious was a person’s illness?

Some studies say that people who carry the virus have antibodies for several months after infection, but other studies show that mutants can change their trajectory.

May 2020 study from placebo-controlled vaccine trial It was found that those who had an older strain of COVID-19 before the South African variant became epidemic did not reduce the risk of re-infection with the South African variant.

“The weakest form of protection looks like innate immunity,” said Mike Famulare, modeler of the Institute for Disease Modeling. “Therefore, the vaccine looks effective or better in that it protects you for a period of 6 months of infection.”

On the other side of the spectrum, people infected with COVID-19 and fully vaccinated may be the most protected from the virus.

“Vaccination with COVID is the most protected thing you can do,” said Famurale.

The Centers for Disease Control and Prevention has changed guidance on when people who test positive for COVID-19 can be vaccinated in the last few months. Patients with COVID-19 can be vaccinated as soon as their symptoms resolve and the quarantine period ends. The only exception to this rule is that if patients are treated with monoclonal antibodies or convalescent plasma in the hospital, the CDC recommends waiting 90 days before those patients are vaccinated.

Initiatives for “herd immunity”

To reach the level of immunity that reduces the rate of virus reproduction, health professionals add up the number of people who naturally acquired immunity to COVID-19 and the immunity obtained by the vaccinated person. ..

In Washington, innate immunity is significantly lower than in other parts of the country, as the inhabitants here adhered to the guidance so well. As a result, life was saved. This means that this state may have more people vulnerable to the virus than other states with high incidences or infections.

According to Famulare, the Institute for Disease Modeling estimates that 10% to 15% of Washington residents have innate immunity to COVID-19 from previous infections.

If this is correct, over 50% of the state’s total population is immune, including 41% of fully vaccinated Washington residents. This is not sufficient for herd immunity levels, and health officials are now aiming to vaccinate more than 70% of Washington residents over the age of 16 to actually repel the virus. I am aiming for inoculation. ..

According to Famurale, the actual herd immunity threshold is difficult to calculate due to the ever-changing nature of the virus, and even when the magic threshold is reached, COVID-19 does not disappear immediately.

“Today’s herd immunity may not be herd immunity tomorrow, so there will be cat and mouse games to play with this virus for months,” he said.

What will happen to the future

COVID-19 does not disappear even if the vaccination rate is high, especially in areas where the vaccination rate is low. It’s possible that they didn’t even see the end of the vaccine campaign.

Dr. John Lynch, an infectious disease specialist at the University of Washington, said this month that he still has solid ideas for annual vaccinations and boosters.

Mutants continue to mutate in these non-immune environments, although risks remain for unvaccinated people and communities. So far, vaccines have countered mutants, but things can get even more difficult if they change in the coming months or years.

“Is it theoretically possible for mutants to surpass vaccine immunity? I think it’s a theoretical concern,” Lynch said.

Gupta believes that this fall and winter could be a “dangerous scenario”, especially due to seasonal changes, people gathering indoors, and lack of herd immunity. Hospitalizations can surge again.

“There is a clear concern that it might happen,” Gupta said.

The future that Gupta is worried about is already happening on a small scale in some places where vaccination rates are low today. Ask health officials in northeastern Washington, where the outbreak overwhelmed the Republic’s Critical Access Hospital after the Superspreading event.

Approximately 30% of each county in northeastern Washington is fully vaccinated, leaving the vast majority of people vulnerable to the virus. Local health officials cannot accurately indicate the number of people who are infected with the virus and may have some degree of immunity, but as many as the region’s immunity exceeds 50%. May not be.

“In eastern Washington, we’re in this weird position to deal with vaccinations longer than in the more vaccinated west, and the current situation is reflected in our numbers,” says Dr. Sam Alzis. .. A health official in the Northeastern Tri-County Health District said earlier this month.

Ultimately, there is no hard stop in a pandemic where the virus has just disappeared. Famulare believes that this year is likely to bring a sort of regulation to the virus in our lives, rather than a sudden end of the pandemic. What it looks like depends heavily on the vaccination rate.

“(Either) the way we live with the virus is different, and better because it’s ugly because everyone is vaccinated or more people die because they aren’t vaccinated.” He said.

Arielle Dreher’s report on The Spokesman-Review is partially funded by the Report for America and members of the Spokane community. This story can be republished for free by other organizations under a Creative Commons license. Contact our newspaper for more information. Editor-in-chief.