Monday, May 31, 2022

Reinfect, rebound, repeat. We shouldn’t be surprised that you can get COVID more than once. Viruses are not all the same. You can get only measles once. Most people living in the United States before 1957 (like me) are immune because they’ve already had it. If you’ve had chicken pox, the virus may lie in wait and return years later as shingles. You can catch a cold more than once. And you can get COVID over and over again. Reinfection and rebound are in the news. Let’s start with rebound:

Rebound: The CDC issued a health advisory on May 24, 2022, concerning COVID-19 rebound which can happen after treatment with the antiviral Paxlovid. Paxlovid tablets are used to treat people who test positive for COVID-19 to prevent serious outcomes. In some cases, a person who tests negative after treatment can revert to testing positive again, with or without symptoms. One study suggests that this is because the Omicron variant has a higher viral load which may cause it to linger longer than earlier variants. The rebound effect has also been seen in patients without Paxlovid. It may be just something the virus does, not something caused by the antiviral treatment.

According to the CDC, the treatment is still effective in preventing severe illness, hospitalizations, and death even if there is a rebound. The health advisory suggests taking precautions because the patient who turns positive may transmit the virus to others.

Reinfection happens when someone recovers from COVID and then later gets it again. Reinfection can be affected by many variables, some originating with the individual and some from the virus itself.

COVID infections, CDC MMWR, May 31, 2022
  1. Individual variables:
    • About 60% of the population has had COVID. This is not a gradual increase. Note in the above graph, the number of cases is almost flat until December, 2021. December was when the B.1.1.529 Omicron variant became prevalent and cases peaked. The greatest increases were in children under 18.
    • At the same time, 77.7 % of the U.S. population has received at least one vaccination against COVID
    • Some people have hybrid immunity–from being both vaccinated and infected
    • Immunity fades over time, which may vary with age, source of immunity, etc.
    • Intensity of viral exposure or viral load can affect the immune response
    • People’s immune systems vary. They may have a robust immune response or a weak one, depending on their age and state of health.
  1. The virus:
    • Variants: Omicron and its variants appear to be more contagious and more adept at breaking through the immune defenses that the earlier variants.
    • Immunity to one variant may not be fully protective against a newer variant.
    • The variants are constantly changing. Notice in the graph below how BA.2.12.1 is taking over and BA.1.1 has been almost eclipsed over 3 months. Remember Delta? Long gone.
Monitoring Variant Proportions, CDC, May 31, 2022.

A growing number of studies purport to measure how long immunity lasts for people that have had COVID and for people who have been immunized and for people who have had both the disease and the shot. A recent study in the New England Journal of Medicine reports that people who have had COVID may be immune for as long as a year (link below). Usually, though, the length of protection is measured in months, not years. People who have had both, referred to as “hybrid immunity,” seem to have a stronger immunity. But as you can see from the graph above, any study that has been around long enough to be published was done on yesterday’s variant.

This virus continues to be both a moving target and a constant part of our environment. Most likely reinfections will continue to occur. What this means in terms of day-to-day living with COVID and COVID’s long-term effects remains to be seen.

Today’s Notable Headlines

“You Are Going to Get COVID Again … And Again … And Again,” The Atlantic, May 27, 2022. https://www.theatlantic.com/health/archive/2022/05/covid-reinfection-research-immunity/639436/

“Sixty seconds on . . . covid rebound,” The BMJ, May 30, 2022. https://www.bmj.com/content/377/bmj.o1365

“Most Americans Have Had COVID-19. That Doesn’t Mean They Won’t Get It Again,” Time, April 29, 2022. https://time.com/6171943/how-long-does-covid-immunity-last/

“How many Americans have had COVID? New CDC study suggests most have contracted it,” Miami Herald, April 26, 2022. https://www.miamiherald.com/news/coronavirus/article260784202.html

Other Sources

Measles, Mayo Clinic, https://www.mayoclinic.org/diseases-conditions/measles/symptoms-causes/syc-20374857#:~:text=If%20you’ve%20already%20had,they’ve%20already%20had%20it.

“COVID-19 Rebound After Paxlovid Treatment,” May 22, 2022. CDC Health Advisory. https://emergency.cdc.gov/han/2022/pdf/CDC_HAN_467.pdf

“Seroprevalence of Infection-Induced SARS-CoV-2 Antibodies — United States, September 2021–February 2022,” CDC, Morbidity and Mortality Weekly Report, April 29, 2022. https://www.cdc.gov/mmwr/volumes/71/wr/mm7117e3.htm?s_cid=mm7117e3_w#F1_down

“Monitoring Variant Proportions,” CDC, May 31, 2022. https://covid.cdc.gov/covid-data-tracker/#variant-proportions

“Protection against SARS-CoV-2 after Covid-19 Vaccination and Previous Infection,” New England Journal of Medicine, March 31, 2022. https://www.nejm.org/doi/10.1056/NEJMoa2118691?url_ver=Z39.88-2003&rfr_id=ori:rid:crossref.org&rfr_dat=cr_pub%20%200pubmedred%20to%20neutralize%20the%20virus

Why am I doing this?

The pandemic hit like a tsunami and the ripple effect will be felt for decades. World upheavals, deglobalization, housing shortages, the Great Resignation, supply chain disruptions–we’re navigating changes not entirely caused by the pandemic, but accelerated by it. Since March 11, 2020, this blog has examined the modern pandemic experience in the media and in everyday life, drawing on my experience as a medical technologist, a historian, and an ordinary person living through extraordinary times.

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