Just started a new job this year, but I've been falling sick way more than usual. Would it be wise to look for another job? Any tips?

Maybe you can feedback to the management and get them to fix the issue?

At least try to provide your feedback to them.

The market isnt very good right now, people are being laid off so its not very wise if you keep changing jobs because of ventilation issue.

Im sure there is a proper way to handle this issue and running away isnt a good solution.

Hey Anon!

Wow, from 0 to 8 MCs is quite bad for a healthy, food conscious, regularly exercising person. The unofficial hours of downtime, recovery, feeling sick is quite a horrendous experience.

When it comes to air ventilation, well, you can't do anything much. Temperature-wise, buy fan, buy sweater respectively. Also, as highlighted by PZL, getting an air purifier may help.

With everyone falling sick and catching viruses, then it's something that needs your office's entire engagement.
You may be leading a healthy lifestyle, but your colleagues may not.

You'd have to take a more active approach.

Get everyone to drink more water; 100plus / aquarius etc if feverish. Buy Vitamin C tablets to share. Or vit c soluble tablets and water lol.

Get some facial masks and place them in the office common area and if you're sick, wear them. Just offer your colleagues if they're sick. You'd need to psycho your HR department to follow your steps too :)

It's gonna be tough if your colleagues are stubborn, but if they're nice and proactive, these things may help.

Last resort: Ask the boss to change office. Or you gotta consider changing jobs.