From the Experts

Seasonality of COVID-19

Severe acute respiratory syndrome Coronavirus 2 (SARS-CoV-2) is the key agent of the novel ongoing pandemic, Coronavirus 2019 (COVID-19). Though there are still many unknowns, we have learned about immunity regarding SARS-CoV-1(the virus that first appeared in 2003). Researchers have presented studies, showing what immunity of the Coronavirus in the current pandemic could look like.

From the Fall of 2016 to 2018, a group of researchers at Columbia University in Manhattan conducted a study to see if the immunity of the Coronavirus protected patients from getting infected multiple times. Researchers collected nasal swabs from first responders, educators, and 191 children. The participants were asked to document symptoms including a sore throat and sneezing. This study showed that the individuals were consistently re-infected with the same Coronavirus, many cases relapsing in the same year. The report also indicated that one of the participants had tested positive again only four weeks after initial recovery. In conclusion, it is fair to say that the immunity of the Coronavirus SARS-CoV-1diminishes rapidly.

The World Health Organization (WHO) is currently measuring the antibodies specific to COVID-19. Antibodies are proteins in the blood that bind to and recognize foreign substances such as bacteria or viruses and produce a response in order for the immune system to clear the virus. Usually, the cells that create antibodies called B lymphocytes also create memory cells. These memory cells remember foreign substances in order to respond and decrease the time of antibody production in future infections. The WHO suggests this is not true. According to the WHO, when they looked at the antibody response of SARS-CoV-2 the agent of COVID-19, they noticed that some individuals showed levels of antibodies for the virus in their system, but others had only small amounts. In late April 2020, the WHO released a scientific brief making it clear that “there is currently no evidence that people who have recovered from COVID-19 and have antibodies are protected from a second infection.”

Many studies have proven that the statement released by the WHO claiming that there is no evidence that antibodies are protective, is false. Cold Spring Harbor Laboratory, bioRXiv, conducted a study in which healthy monkeys were exposed to the virus and tested positive, and were exposed to the virus again after recovery. Results demonstrated that when the monkeys were challenged with the SARS-CoV-2 strain after recovering the first time, their immune system was not overtaken by the virus. Although some research has proven that antibodies help fight against recurrent infections, it is stressed that this does not mean that individuals should ignore public health advice and assume they are not at risk for a second infection.

Bottom Line Up Front:
● Our immune system reacts differently to COVID-19 than other viruses.
● There is a risk of a second infection.

“Immunity passports” in the context of COVID-19. World Health Organization. Accessed April 29, 2020.

Regalado A. What if immunity to covid-19 doesn’t last? MIT Technology Review. Published April 27, 2020. Accessed April 29, 2020.