Thanks for your question on HCM. Pneumonia is infection of lung parenchyma. And it is contagious disease. And spread by droplet infection mostly. When a patient of pneumonia coughs or sneezes, organism come in the environment as droplets and these droplets can be inhaled by normal individuals and can cause infection in lung (pneumonia). So possibility of infection in the weekend is high. And pneumonia vaccine is effective only against organism which is covered by the vaccine. So may be some other organism has infected her and cause pneumonia. Better to consult pulmonologist and start treatment.