Post vaccination fatigue

An elderly 69 yr old male patient complained of side effects after taking the first dose of covid vaccine.  He developed a severe rash across his back and chest which lasted for about 3 days. As the rash started resolving slowly he got extreme fatigue. He could barely get up from bed and walk or carry out his regular routine. He was quite a fit guy for his age and was still running his own company. All his vital parameters were normal and he was mentally calm and stable. He was given homeopathy sulphur 30C 4 drops TDS along with oral glutathione tablets (2 tablets a day). Next day itself his fatigue had started improving and felt like his normal self.