The study found that kids and adults made broadly similar antibody responses after exposure to SARSCoV2 - remarkably, kids made higher antibody levels against all 4 different parts of the virus that were tested. They also found that kids retained antibodies better than adults up to 12 months after infection. While some kids and adults lost Nucleocapsid (N) antibodies over time, Spike (S) protein antibody levels remained high in nearly all the kids at 12 months but waned in many adults. SARSCoV2 antibodies in kids who were infected with the original strain back in the first wave in March 2020 were able to efficiently neutralize the original virus strain, as well as alpha, beta and delta variants (in the laboratory) to the same extent as adults. The majority of kids who had been exposed to SARSCoV2 also developed robust and long-lasting T cell responses after infection, at least 2-fold higher than in adults, and specifically targeting the spike protein. Cellular responses were retained for at least 6 months. Unexpectedly, they also found that some kids without any SARSCoV2 antibodies had T cell immunity against the virus - most likely because of recent infection with more common endemic seasonal coronaviruses.
Image: Theodor Matthei, Cleopatra with the snake, 1897.