What we know so far (previous posts, with of course the scientific studies, are linked at the bottom):
• Antibodies develop following the majority of COVID19 infections (yes among both symptomatic and asymptomatic cases) • Antibodies are detectable by 19 days of symptom onset • Antibodies last at least 3 months. Which is fantastic news, because these studies were only three months long
What we don’t know so far: • How long antibodies “truly” last. Unfortunately, this just takes time. If COVID19 antibodies are anything like its cousins (SERS and MERS), we would expect 2-3 years. • How well the antibodies protect us from reinfection.
Well, a new study gives us a glimpse on our second unknown: antibody protection from reinfection
May 18-19: Before leaving for sea, all 122 crew members (113 men and 9 women) were tested for COVID19 and COVID19 antibodies. No one tested positive for an active COVID19 infection. 3 crew members tested positive for antibodies.
May 20: The fishing vessel left for sea from Seattle, Washington
June 5: Ship comes back because one person has symptoms (then tested positive and then was hospitalized). Everyone else was tested too and followed up for an average of 35 days.
June 12: By this date, 98 crew members tested positive
June 22: By this date, another 3 crew members tested positive
By end of study: 104 crew members (85.2% attack rate) tested positive for COVID19. 0 of the 3 crew members that had antibodies prior to departure tested positive for active COVID19 infection nor did they have any symptoms.
Translation? In this case study, antibodies are associated with protection against re-infection from a slightly different strain. This is great news, especially when we are working desperately and tirelessly for vaccines.
Previous post: How long do antibodies last? https://yourlocalepidemiologist.com/how-long-do-antibodies-last/
Previous post: “Natural herd immunity” and antibodies: https://yourlocalepidemiologist.com/herd-immunity-and-antibodies/
Picture: This is an actual picture of the fishing vessel thanks to Michael Brunk/nwlens.com