<story><title>Antibody levels highly predictive of immune protection from symptomatic Covid</title><url>https://www.nature.com/articles/s41591-021-01377-8</url></story><parent_chain><item><author>xiphias2</author><text>My father tested negative for spike specific antibodies 2 weeks after the 2nd Pfizer vaccine (he&amp;#x27;s not the only one), and as I didn&amp;#x27;t find any data on people who test negative (and I know that the vaccine has 94% efficiency preventing COVID), he&amp;#x27;s still mostly not leaving his apartment.&lt;p&gt;He&amp;#x27;ll have a test against the viruses themselves next week, but he&amp;#x27;ll need to wait 2 weeks for the result for that test.</text></item></parent_chain><comment><author>azinman2</author><text>That doesn’t mean he doesn’t have protection. The antibody tests only look For one thing, but the body has many mechanisms of protection from the vaccine. That is one of the reasons why they’re not suggested to be used for the general population.</text></comment>
<story><title>Antibody levels highly predictive of immune protection from symptomatic Covid</title><url>https://www.nature.com/articles/s41591-021-01377-8</url></story><parent_chain><item><author>xiphias2</author><text>My father tested negative for spike specific antibodies 2 weeks after the 2nd Pfizer vaccine (he&amp;#x27;s not the only one), and as I didn&amp;#x27;t find any data on people who test negative (and I know that the vaccine has 94% efficiency preventing COVID), he&amp;#x27;s still mostly not leaving his apartment.&lt;p&gt;He&amp;#x27;ll have a test against the viruses themselves next week, but he&amp;#x27;ll need to wait 2 weeks for the result for that test.</text></item></parent_chain><comment><author>yosito</author><text>I wonder if an expert could chime in on this. If someone tests negative for antibodies a few weeks after a vaccine, should that person get vaccinated again? Maybe with a different vaccine?</text></comment>