A strong immune system can be the difference between shrugging off a cold and being wiped out for days.
Where you live could play a bigger role than you think, and choosing to spend your time in certain parts of the world could place you in a better position.
The world's best countries for your immune system have now been revealed.
As part of the World Immunity Report, experts at Nature's Best compiled the list of the best countries, giving an overall score based on factors such as average temperature, obesity rates, average age, average rainfall, damp searches, mould searches, pollution and smoking rates.
The top spot went to Morocco, scoring an impressive 63.4 out of 80 in the ranking.
The North African country has one of the lowest levels of average annual rainfall (215mm) and ranked highly for its warm climate, with an average temperature of 19.2°C.
It also performed well on obesity levels, with just 22.1 per cent of the population classified as obese.
India followed in second place with a score of 54.2.
Morocco has been ranked as the best country in the world for immune health
The country recorded one of the highest average temperatures among the 30 nations analysed (25.4°C), helping secure its position near the top of the rankings.
Obesity also stood out as a key lifestyle factor here, with levels at just 7.2 per cent nationally.
In third place was South Africa, with a score of 53.7.
Rounding out the top five were Tunisia (52.7) and Egypt (51.1).
Next up were Denmark, the Dominican Republic and Canada, followed by Malaysia and Albania - making the top 10.
In contrast, the US and UK both appeared in the bottom five.
They had scores of 30.4 and 28.5 out of 80 respectively.
This was largely due to higher obesity and smoking rates.
Top 10 countries for your immune system
- Morocco - 63.4/80
- India - 54.2
- South Africa - 53.7
- Tunisia - 52.7
- Egypt - 51.1
- Denmark - 45
- Dominican Republic - 44.8
- Canada - 44.1
- Malaysia - 43.8
- Albania - 43.3
Swapping Morocco for the UK means exchanging year-round sunshine and warm, dry air for cooler temperatures and cloudier skies, and the rankings reflect that contrast.
The UK placed 28th, with a score of just 28.5.
Lower average temperatures of just nine degrees and obesity rates of 28.7 per cent dragged the score down.
The 2026 World Immunity Index was published by Nature's Best, a UK-based supplements company.
Lucy Kershaw, nutrition expert at Nature's Best, said: 'Your immune system isn't just something to think about when you're sick. Where you live, how you eat and how much you move can all add up.
'The good news is that with small daily changes you can help your immune system all year round.'