Sadly, politicians and a liberal news media are trying to rewrite the science on antibodies. When the whole world is looking for hope for a way out of this corona virus pandemic, these people are questioning the protection that antibodies provide against reinfection with the virus.
Manish Butte, an associate professor and chief of pediatric allergy, immunology and rheumatology at UCLA, and Andrew Bogan, a molecular biologist, write in The Wall Street Journal to help clarify the science behind antibodies. They discuss two type of immune responses to viral infection: innate response and adaptive response.
Innate response occurs within minutes to hours and triggers alarms that result in effects across the body such as fever. Tissues and cells produce “interferons”, molecules that incapacitate many viruses and recruit white blood cells to destroy them. For mild infections, innate responses are sufficient to defeat the virus.
But some viral infections require a second wave of response, adaptive response, which arrives four or five days after infection. Molecular bits of the offending pathogen, known as antigens, are brought to the lymph nodes, where white blood cells called T and B lymphocytes attack the infected tissues, such as the lung for Covid-19. They release cytotoxins to kill infected cells. The over-aggressive immune response causes much of the devastation seen in severe cases of the disease.
As a result of this response, B cells produce antibodies that over several weeks adapt to the pathogen. After the war is over, a few T and B cells linger in the lymph nodes and in the mucosa of the airways, forming an “immunological memory” that is programmed to fight faster and stronger the next time that pathogen appears. This cell memory provides “protective immunity”, which Thucydides first hypothesized in 430 B.C.
For decades, antibody tests have been used as proof of immune response, arising either from infection or vaccination. The presence of antibodies can be detected from a blood sample using a serologic assay. Several tests have published sensitivity and specificity values as high as 99.6% to 100%. These tests are consistent with other antibody tests, such as those for mononucleosis and hepatitis infections, that are in routine use without much concern about their accuracy.
Which brings us to the question, “Why are people doubting the accuracy of antibody tests and claiming they don’t protect people from reinfection with the Covid-19 virus?
Butte and Bogan respond:
“Given the reliability and performance of these tests, it appears to be politics, not science, that is behind the claim that the presence of specific antibodies in those who’ve recovered from Covid-19 doesn’t indicate protective immunity. This is baffling. If it’s true, how does anyone recover from a severe infection?
If these antibodies aren’t protective, then global efforts to develop a vaccine are pointless. Vaccines try to arm T and B cells so they fight quickly when exposed to the virus. If antibodies detected in a person who has recovered don’t confer immunity, then neither would antibodies developed in response to a vaccine. The far more likely scenario, which is true of other corona viruses, is that antibodies do offer protection for a significant duration, so that a successful vaccine could be developed.”
The greatest disappointment of this virus pandemic may be the politicization of the response by those who would prefer a prolonged fear of the virus and shutdown of the economy for months to come – or at least until after the November presidential election.