There has been so much confusion and conflicting answers to questions of whether having immunity to COVID-19 is long-lasting, especially if you have mild infection. The way to really answer this question is to deliberately infect people who have recovered from COVID-19 with the SARS-CoV-2 virus again. That is wholly unethical.

Yet, a COVID-19 outbreak in May 2020 on a fishing vessel in Seattle may have done the same thing. The vessel had to return to shore 18 days after it had departed because one of the 122 people on board became very sick and needed hospitalization. Prior to departure, all 122 people were tested for COVID infection and for the presence of antibodies. Three people had what was called “neutralizing antibodies,” which means antibodies that inactivate the virus from infection.

They had data on 120 of the 122 crew members of the ship. Of the 117 people without antibodies, 103 tested positive for COVID-19. None of those with the neutralizing antibodies became infected. They did statistical analysis on these findings, and they found that this result had a 0.2% probability of being due to random chance.

Yes, this was a small study on one fishing vessel that had an outbreak. At the same time, it offers me — as a doctor who has been fighting COVID-19 on the front lines — hope that a vaccine that generates a similar neutralizing antibody response can actually work and offer protection against infection with SARS-CoV-2.

Of course, I will need to see the data, and I will not take a vaccine that has been rushed to market. At the same time, this study — with all its limitations — is encouraging to me, and it offers me hope that a good, safe, and effective vaccine will eventually work. In the midst of this pandemic that has so much darkness, we need some good news like this to bring us some light.