What is the job of Vaccine? To prevent the diseases?
Do you wish ultimate formula for vaccine?

Here you go:

देवश्याना से देवोत्थान एकादशी (2 months of monsoon, 2 months of post-monsoon sharad): स्वाध्याय, संशोधन, स्वधर्म, स्वाहा, स्वधा ,व्रत, उपवास
देवोत्थान से देवश्याना एकादशी(8 months of हेमंत,शिशिर,वसंत,ग्रीष्म) : गृहसंसार, अर्थ-उपार्जन, समाजलक्षी कर्म, राष्ट्र सेवा, यात्रा-प्रवास , अखाडा, खेल-क्रीडा, उत्सव

When frogs are out, you should be in.
When frogs are in, you should be out.

If you start syncing bodily rhythm with seasons, performing major activities of the day as per season, there is no doubt that immunity will work in your favor!

विष्णु is the sustaining force in our body as a reflection of the universe. (यथा पिंडे तथा ब्रह्मांडे) देव उठनी #एकादशी when he takes control back from body-mind running on auto-pilot for 4 months!
For next 8 months, we are allowed to take part in all physically and mentally challenging activities. Agriculture, War, New Venture, Marriage, Child planning. Good time of the year where we need help from विष्णु! Three seasons of productive hours. (हेमंत,शिशिर,वसंत) and 1 season for preparing again for auto-pilot. (ग्रीष्म)
For चातुर्मास (वर्षा,शरद), change in activities is prescribed. Mainly such activities which supports auto-pilot mode and does not put stress on dormant senses.