Medical supplies from the UK arrived in India on Tuesday - the first international shipment aimed at stemming a devastating Covid-19 surge.
Ventilators and oxygen equipment landed in Delhi, but far more will be needed, with India recording 320,000 new infections on Tuesday, and deaths rising close to 200,000 overall.
Many hospitals are overwhelmed, with people waiting in the streets outside.
The US, France and Germany are among nations sending desperately needed aid, reports the BBC.
One doctor and government adviser working in Mumbai, Zarir Udwadia, told the BBC's Today programme the currently pledged supplies were a "drop in the ocean" that would have limited effects. He said he was seeing "ward after ward full of patients struggling to breathe on ventilators of different forms and shapes".
Dr Udwadia said the complacency over getting vaccinated during the first wave had now given way to long lines of people outside medical centres jostling to get shots.
"Vaccine hesitancy has become vaccine desperation," he said.
Although India's statistics currently stand at 17.6 million cases and 197,500 deaths, some believe the real figures to be much higher. One investigation by NDTV found that over the past week in Delhi alone some 1,158 deaths may have gone unrecorded.
What aid is arriving?
The UK shipment of 200 pieces, including ventilators and oxygen concentrators - which will help hospitals manage oxygen supplies - was unloaded at Delhi airport on Tuesday.
Foreign ministry spokesman Arindam Bagchi said it was "international co-operation at work", but it is just the first trickle in what needs to be a flood of supplies for a nation of 1.3 billion people.
US President Joe Biden said on Monday he would send up to 60 million doses of the AstraZeneca Covid-19 vaccine abroad and, although the destinations were not given, India could be a prime recipient.
The World Health Organization chief, Tedros Adhanom Ghebreyesus, said it was "doing everything we can, providing critical equipment and supplies".
France is sending oxygen production units, as well as oxygen containers and respirators, and some shipments of empty cylinders have already arrived from Thailand and Singapore.
And India has stepped up its own efforts - the first "Oxygen Express" train, which aims to transport 70 tonnes of the gas, arrived in the capital.
The surge varies from state to state, with Maharashtra, Uttar Pradesh, Karnataka and Kerala, along with Delhi, among those badly affected.
Around many Indian cities, images show people waiting outside hospitals in ambulances or lying on makeshift beds, while elsewhere flames rise from the funeral pyres of victims.
What is the vaccine situation?
It is one of rising concern.
India has opened vaccination to all adults from 1 May - another 900 million people - but there are fears supplies from the two Indian sources, the Serum Institute of India and Bharat Biotech, cannot even meet current demands for the over 45s.
The government denies there is any shortage of vaccines and has approved funds to boost production at the Serum Institute to 100 million doses a month by the end of May.
But health ministers from some states say they have been warned they may not get the supplies they need - particularly given the surge in demand from the public.
India has so far administered initial jabs to about 10 per cent of the population.
Dr Udwadia told the BBC the rollout had been "glacially slow" and at this rate the country would not reach anything approaching herd immunity within 600 days.
He said that, because of the limited effects of the first wave: "We let down our collective guard and we were urged to by our leaders. Instead of being asked to be vigilant we heard self-congratulatory declarations of victory."