Catherine is 33, and too weak to move.
Catherine (centre) and her daughter (left) (Photo: © Don McCullin)
She is one of the millions of women worldwide living with HIV.
She has been in hospital three times since January 2004 and knows she is very ill.
Catherine lives at Nkwazi compound in Ndola, Zambia. She despairs over the future of her three sons, aged 14, nine and two.
"Yes, I am HIV-positive. I found out last year but I don't know how I got infected.
"My husband thinks he may also be ill," she said.
Of the youngest, she said: "Kenan has no good future, he is often ill like me."
Catherine does not have access to antiretroviral therapy.
Nomalunga, 23, from the Khayelitsha township in Cape Town, South Africa, was luckier.
In 2000, she received a drug called AZT during the delivery of her baby to prevent HIV passing to her daughter, Zikhona, who is now a healthy four-year-old.
After the birth Nomalunga was underweight and feeling extremely unwell.
"I was so sick then, I thought I would die. I didn't
know there were different stages in this disease and
I thought once you had HIV you died very soon," she said.
In September 2002, Nomalunga began on antiretroviral therapy.
"It was amazing. Before, I was losing weight and I had meningitis too.
"Then I gained weight very quickly and felt stronger.
I had no side-effects, and just once had a case
Nomalunga was so inspired by the change in her
health, and so optimistic for her own and her
daughter's future that she has trained with the Red
Cross as a carer.
Mavis, right, with her grandmother, Margaret (Photo: © Don McCullin)
It is not only adults who are carers.
Mavis and her brother Aaron,13, live in Ndola, Zambia and have lost both their parents to HIV.
"We miss our mother," said Aaron.
"When she was ill, we swept the house, washed the clothes and fetched water.
"We liked looking after her because she was our mother."
They both now live with their grandparents.
Both case studies are featured in "If not now, when? HIV drugs and prevention" a new report released on November 23 by the charity Christian Aid with photographs by Don McCullin.