How Soon After the Vaccine are you Immune?

I did look on lesser-parts of the Internet. There seems to be no obvious answer.

After I get the vaccine how long must I wait before I start kissing random people again? When will I be immune?

After the second shot of the Pfizer vaccine (3 weeks after the first) you should reach maximum effectiveness in 7-10 days. This might still change as we start seeing the results from millions being immunized.

The very good news, is even before the 2nd shot, the vaccine is over 80% effective.

I have to stress; No one is promising immunity.

Another caveat, the studies only show that the vaccine prevent people from developing symptoms, not preventing infection. Something else we should learn over the next month or two.

Last caveat, You and I might not get the Pfizer vaccine, we may get one of the other ones still in the development chain. Moderna’s should roll out soon and requires much lesser refrigeration. There are several one shot vaccines in development also.

I assume the earliest I’ll get any vaccine is April as I’m not in any high risk group.

I am old & fat so I have a lot going for me. Thank you.

AFAIK there is no evidence yet that the Pfizer or Moderna vaccines keep the virus from spreading. They were not designed to prevent transmission of the bug.

See my These Vaccines Don’t Prevent Transmission of the Virus? thread.

Please help me understand:

If I get the vaccine, I can have the virus in my body and carry it to someone who’s not gotten the vaccine and infect them? But I won’t have symptoms myself?

Basically the same as un-vaccinated folks who test positive but never had symptoms.

That is my understanding. Also, and somebody please correct me if you know different, you can still get symptoms and even get COVID but it will (likely) be a mild case. IOW you probably won’t die from it. I guess.

More and more studies show that the vaccines reduce transmissiiblity – at least the Pfizer vaccine, and probably the others as well.

With Moderna, at about day 12, diagnoses of Covid-19 appear to drop off considerably. The average person probably has a good level of immune protection at day 7. The mean time from infection to diagnosis is five days.

The WHO says the first shot is 92% effective at preventing Covid-19 at day 14.

You can be infected without getting Covid-19.

About half the people who get the first shot have neutralizing antibodies at day 15. Everyone has neutralizing antibodies 7 days after the second shot.

My view is that at day 14, you can be take some piece of mind, but you should maintain your same actions at preventing infection until 10 days after the second shot for your own safety. You should remain vigilant to protect others until they have good immune protection.

This ^

The vaccine reduces transmissibility; it doesn’t eliminate the threat entirely. It’s important to remain vigilant. Until we really succeed at slowing transmission rates to under a percent, we need to see the vaccines as a layer of protection – arguably the strongest layer but still a layer. We will still need to abide by and encourage distancing, mask wearing, and other measures.

As others have already mentioned, the additional information has rolled in now, 2 months after my post. It looks like the vaccines great decrease the transmission rate also. This is great news and pretty much what was hoped for.

I don’t think the medical community ever expected the vaccines to equal no transmission and there was little enough known in December that reports were being cautious the vaccines were going to prevent transmission.

From the data released by the FDA today, it looks like for the J&J vaccine, I’d lean towards waiting 28 days. Considering it’s only 1 shot, that’s still quicker than Pfizer or Moderna.