I would ask the government if they could recommend vitamins and minerals that aid the bodies natural immunity to be made available free on the NHS. There is scientific evidence that vitamins such as vitamin D, vitamin C & Iron & Zinc, Vitamin E, Vitamin B6 at the highest recommended dose will Heighten peoples natural immunity. I feel this would be extremely beneficial to many vulnerability groups in the UK.

A few key micronutrients have been identified as critical for the growth and function of immune cells, including:
Iron. Iron is a component of enzymes critical for immune cell function. ...
Vitamin A. 
Vitamin C. 
Vitamin D. 
Vitamin E. 
Zinc.

Examples:

Vitamin C: is one of the biggest immune system boosters of all. In fact, a lack of vitamin C can even make you more prone to getting sick. Foods rich in vitamin C include oranges, grapefruits, tangerines, strawberries, bell peppers, spinach, kale and broccoli. Daily intake of vitamin C is essential for good health because your body doesn’t produce or store it. The good news is that vitamin C is in so many foods that most people don’t need to take a vitamin C supplement unless a doctor advises it.

Vitamin B6: is vital to supporting biochemical reactions in the immune system. Vitamin B6-rich foods include chicken and cold-water fish such as salmon and tuna. Vitamin B6 also is found in green vegetables and in chickpeas, which is the main ingredient in hummus.

Vitamin E: is a powerful antioxidant that helps the body fight off infection. Foods rich in vitamin E include nuts, seeds and spinach.

Vitamin D: is a fat-soluble nutrient essential to the health and functioning of your immune system. Vitamin D enhances the pathogen-fighting effects of monocytes and macrophages — white blood cells that are important parts of your immune defense — and decreases inflammation, which helps promote immune response.